diff --git a/lib/granblue/transformers/base_deck_transformer.rb b/lib/granblue/transformers/base_deck_transformer.rb
new file mode 100644
index 0000000..b6a7faa
--- /dev/null
+++ b/lib/granblue/transformers/base_deck_transformer.rb
@@ -0,0 +1,91 @@
+# frozen_string_literal: true
+
+module Granblue
+  module Transformers
+    class BaseDeckTransformer < BaseTransformer
+      def transform
+        Rails.logger.info "[TRANSFORM] Starting BaseDeckTransformer#transform"
+        Rails.logger.info "[TRANSFORM] Data class: #{data.class}"
+
+        # Handle already transformed parameters
+        if data.is_a?(ActionController::Parameters) && data.key?(:name)
+          Rails.logger.info "[TRANSFORM] Found existing parameters, returning as is"
+          return data.to_h.symbolize_keys
+        end
+
+        # Handle raw game data
+        Rails.logger.info "[TRANSFORM] Processing raw game data"
+        input_data = data['import'] if data.is_a?(Hash)
+        unless input_data
+          Rails.logger.error "[TRANSFORM] No import data found"
+          return {}
+        end
+
+        Rails.logger.info "[TRANSFORM] Found import data"
+        deck = input_data['deck']
+        pc = deck['pc'] if deck
+
+        unless deck && pc
+          Rails.logger.error "[TRANSFORM] Missing deck or pc data"
+          Rails.logger.error "[TRANSFORM] deck present: #{!!deck}"
+          Rails.logger.error "[TRANSFORM] pc present: #{!!pc}"
+          return {}
+        end
+
+        Rails.logger.info "[TRANSFORM] Building deck data structure"
+        result = {
+          lang: language,
+          name: deck['name'] || 'Untitled',
+          class: pc.dig('job', 'master', 'name'),
+          extra: pc['isExtraDeck'] || false,
+          subskills: transform_subskills(pc['set_action']),
+          characters: transform_characters(deck['npc']),
+          weapons: transform_weapons(pc['weapons']),
+          summons: transform_summons(pc['summons'], pc['quick_user_summon_id']),
+          sub_summons: transform_summons(pc['sub_summons']),
+          friend_summon: pc.dig('damage_info', 'summon_name')
+        }
+
+        Rails.logger.info "[TRANSFORM] Completed transformation"
+        Rails.logger.debug "[TRANSFORM] Result: #{result}"
+
+        result
+      end
+
+      private
+
+      def transform_subskills(set_action)
+        Rails.logger.info "[TRANSFORM] Processing subskills"
+        unless set_action.is_a?(Array) && !set_action.empty?
+          Rails.logger.info "[TRANSFORM] No valid set_action data"
+          return []
+        end
+
+        skills = set_action[0]
+        unless skills.is_a?(Array)
+          Rails.logger.info "[TRANSFORM] Invalid skills array"
+          return []
+        end
+
+        results = skills.map { |skill| skill['name'] if skill.is_a?(Hash) }.compact
+        Rails.logger.info "[TRANSFORM] Found #{results.length} subskills"
+        results
+      end
+
+      def transform_characters(npc_data)
+        Rails.logger.info "[TRANSFORM] Processing characters"
+        CharacterTransformer.new(npc_data, options).transform
+      end
+
+      def transform_weapons(weapons_data)
+        Rails.logger.info "[TRANSFORM] Processing weapons"
+        WeaponTransformer.new(weapons_data, options).transform
+      end
+
+      def transform_summons(summons_data, quick_summon_id = nil)
+        Rails.logger.info "[TRANSFORM] Processing summons"
+        SummonTransformer.new(summons_data, quick_summon_id, options).transform
+      end
+    end
+  end
+end
diff --git a/lib/granblue/transformers/base_transformer.rb b/lib/granblue/transformers/base_transformer.rb
new file mode 100644
index 0000000..e49a3df
--- /dev/null
+++ b/lib/granblue/transformers/base_transformer.rb
@@ -0,0 +1,74 @@
+# frozen_string_literal: true
+
+module Granblue
+  module Transformers
+    class TransformerError < StandardError
+      attr_reader :details
+
+      def initialize(message, details = nil)
+        @details = details
+        super(message)
+      end
+    end
+
+    class BaseTransformer
+      ELEMENT_MAPPING = {
+        0 => nil,
+        1 => 4, # Wind -> Earth
+        2 => 2, # Fire -> Fire
+        3 => 3, # Water -> Water
+        4 => 1, # Earth -> Wind
+        5 => 6, # Dark -> Light
+        6 => 5 # Light -> Dark
+      }.freeze
+
+      def initialize(data, options = {})
+        @data = data
+        @options = options
+        @language = options[:language] || 'en'
+        Rails.logger.info "[TRANSFORM] Initializing #{self.class.name} with data: #{data.class}"
+        validate_data
+      end
+
+      def transform
+        raise NotImplementedError, "#{self.class} must implement #transform"
+      end
+
+      protected
+
+      attr_reader :data, :options, :language
+
+      def validate_data
+        Rails.logger.info "[TRANSFORM] Validating data: #{data.inspect[0..100]}..."
+
+        if data.nil?
+          Rails.logger.info "[TRANSFORM] Data is nil"
+          return true
+        end
+
+        if data.empty?
+          Rails.logger.info "[TRANSFORM] Data is empty"
+          return true
+        end
+
+        # Data validation successful
+        true
+      end
+
+      def get_master_param(obj)
+        return [nil, nil] unless obj.is_a?(Hash)
+
+        master = obj['master']
+        param = obj['param']
+        Rails.logger.debug "[TRANSFORM] Extracted master: #{!!master}, param: #{!!param}"
+
+        [master, param]
+      end
+
+      def log_debug(message)
+        return unless options[:debug]
+        Rails.logger.debug "[TRANSFORM-DEBUG] #{self.class.name}: #{message}"
+      end
+    end
+  end
+end
diff --git a/lib/granblue/transformers/character_transformer.rb b/lib/granblue/transformers/character_transformer.rb
new file mode 100644
index 0000000..210228a
--- /dev/null
+++ b/lib/granblue/transformers/character_transformer.rb
@@ -0,0 +1,51 @@
+module Granblue
+  module Transformers
+    class CharacterTransformer < BaseTransformer
+      def transform
+        Rails.logger.info "[TRANSFORM] Starting CharacterTransformer#transform"
+
+        unless data.is_a?(Hash)
+          Rails.logger.error "[TRANSFORM] Invalid character data structure"
+          return []
+        end
+
+        characters = []
+        data.each_value do |char_data|
+          next unless char_data['master'] && char_data['param']
+
+          master = char_data['master']
+          param = char_data['param']
+
+          Rails.logger.debug "[TRANSFORM] Processing character: #{master['name']}"
+
+          character = {
+            name: master['name'],
+            id: master['id'],
+            uncap: param['evolution'].to_i
+          }
+
+          Rails.logger.debug "[TRANSFORM] Base character data: #{character}"
+
+          # Add perpetuity (rings) if present
+          if param['has_npcaugment_constant']
+            character[:ringed] = true
+            Rails.logger.debug "[TRANSFORM] Character is ringed"
+          end
+
+          # Add transcendence if present
+          phase = param['phase'].to_i
+          if phase && phase.positive?
+            character[:transcend] = phase
+            Rails.logger.debug "[TRANSFORM] Character has transcendence: #{phase}"
+          end
+
+          characters << character unless master['id'].nil?
+          Rails.logger.info "[TRANSFORM] Successfully processed character #{character[:name]}"
+        end
+
+        Rails.logger.info "[TRANSFORM] Completed processing #{characters.length} characters"
+        characters
+      end
+    end
+  end
+end
diff --git a/lib/granblue/transformers/summon_transformer.rb b/lib/granblue/transformers/summon_transformer.rb
new file mode 100644
index 0000000..f149c87
--- /dev/null
+++ b/lib/granblue/transformers/summon_transformer.rb
@@ -0,0 +1,73 @@
+# frozen_string_literal: true
+
+module Granblue
+  module Transformers
+    class SummonTransformer < BaseTransformer
+      TRANSCENDENCE_LEVELS = [210, 220, 230, 240].freeze
+
+      def initialize(data, quick_summon_id = nil, options = {})
+        super(data, options)
+        @quick_summon_id = quick_summon_id
+        Rails.logger.info "[TRANSFORM] Initializing SummonTransformer with quick_summon_id: #{quick_summon_id}"
+      end
+
+      def transform
+        Rails.logger.info "[TRANSFORM] Starting SummonTransformer#transform"
+
+        unless data.is_a?(Hash)
+          Rails.logger.error "[TRANSFORM] Invalid summon data structure"
+          Rails.logger.error "[TRANSFORM] Data class: #{data.class}"
+          return []
+        end
+
+        summons = []
+        data.each_value do |summon_data|
+          Rails.logger.debug "[TRANSFORM] Processing summon: #{summon_data['master']['name'] if summon_data['master']}"
+
+          master, param = get_master_param(summon_data)
+          unless master && param
+            Rails.logger.debug "[TRANSFORM] Skipping summon - missing master or param data"
+            next
+          end
+
+          summon = {
+            name: master['name'],
+            id: master['id'],
+            uncap: param['evolution'].to_i
+          }
+
+          Rails.logger.debug "[TRANSFORM] Base summon data: #{summon}"
+
+          # Add transcendence if applicable
+          if summon[:uncap] > 5
+            level = param['level'].to_i
+            trans = calculate_transcendence_level(level)
+            summon[:transcend] = trans
+            Rails.logger.debug "[TRANSFORM] Added transcendence level: #{trans}"
+          end
+
+          # Mark quick summon if applicable
+          if @quick_summon_id && param['id'].to_s == @quick_summon_id.to_s
+            summon[:qs] = true
+            Rails.logger.debug "[TRANSFORM] Marked as quick summon"
+          end
+
+          summons << summon
+          Rails.logger.info "[TRANSFORM] Successfully processed summon #{summon[:name]}"
+        end
+
+        Rails.logger.info "[TRANSFORM] Completed processing #{summons.length} summons"
+        summons
+      end
+
+      private
+
+      def calculate_transcendence_level(level)
+        return 1 unless level
+        level = 1 + TRANSCENDENCE_LEVELS.count { |cutoff| level > cutoff }
+        Rails.logger.debug "[TRANSFORM] Calculated transcendence level: #{level}"
+        level
+      end
+    end
+  end
+end
diff --git a/lib/granblue/transformers/transformer_error.rb b/lib/granblue/transformers/transformer_error.rb
new file mode 100644
index 0000000..be8b13c
--- /dev/null
+++ b/lib/granblue/transformers/transformer_error.rb
@@ -0,0 +1,12 @@
+module Granblue
+  module Transformers
+    class TransformerError < StandardError
+      attr_reader :details
+
+      def initialize(message, details = nil)
+        @details = details
+        super(message)
+      end
+    end
+  end
+end
diff --git a/lib/granblue/transformers/weapon_transformer.rb b/lib/granblue/transformers/weapon_transformer.rb
new file mode 100644
index 0000000..db5e964
--- /dev/null
+++ b/lib/granblue/transformers/weapon_transformer.rb
@@ -0,0 +1,136 @@
+module Granblue
+  module Transformers
+    class WeaponTransformer < BaseTransformer
+      UNCAP_LEVELS = [40, 60, 80, 100, 150, 200].freeze
+      TRANSCENDENCE_LEVELS = [210, 220, 230, 240].freeze
+      MULTIELEMENT_SERIES = [13, 17, 19].freeze
+
+      def transform
+        Rails.logger.info "[TRANSFORM] Starting WeaponTransformer#transform"
+
+        unless data.is_a?(Hash)
+          Rails.logger.error "[TRANSFORM] Invalid weapon data structure"
+          return []
+        end
+
+        weapons = []
+        data.each_value do |weapon_data|
+          next unless weapon_data['master'] && weapon_data['param']
+
+          master = weapon_data['master']
+          param = weapon_data['param']
+
+          Rails.logger.debug "[TRANSFORM] Processing weapon: #{master['name']}"
+
+          weapon = transform_base_attributes(master, param)
+          Rails.logger.debug "[TRANSFORM] Base weapon attributes: #{weapon}"
+
+          weapon.merge!(transform_awakening(param))
+          Rails.logger.debug "[TRANSFORM] After awakening: #{weapon[:awakening] if weapon[:awakening]}"
+
+          weapon.merge!(transform_ax_skills(param))
+          Rails.logger.debug "[TRANSFORM] After AX skills: #{weapon[:ax] if weapon[:ax]}"
+
+          weapon.merge!(transform_weapon_keys(weapon_data))
+          Rails.logger.debug "[TRANSFORM] After weapon keys: #{weapon[:keys] if weapon[:keys]}"
+
+          weapons << weapon unless master['id'].nil?
+          Rails.logger.info "[TRANSFORM] Successfully processed weapon #{weapon[:name]}"
+        end
+
+        Rails.logger.info "[TRANSFORM] Completed processing #{weapons.length} weapons"
+        weapons
+      end
+
+      private
+
+      def transform_base_attributes(master, param)
+        Rails.logger.debug "[TRANSFORM] Processing base attributes for weapon"
+
+        series = master['series_id'].to_i
+        weapon = {
+          name: master['name'],
+          id: master['id']
+        }
+
+        # Handle multi-element weapons
+        if MULTIELEMENT_SERIES.include?(series)
+          element = master['attribute'].to_i - 1
+          weapon[:attr] = element
+          weapon[:id] = (master['id'].to_i - (element * 100)).to_s
+          Rails.logger.debug "[TRANSFORM] Multi-element weapon adjustments made"
+        end
+
+        # Calculate uncap level
+        level = param['level'].to_i
+        uncap = calculate_uncap_level(level)
+        weapon[:uncap] = uncap
+        Rails.logger.debug "[TRANSFORM] Calculated uncap level: #{uncap}"
+
+        # Add transcendence if applicable
+        if uncap > 5
+          trans = calculate_transcendence_level(level)
+          weapon[:transcend] = trans
+          Rails.logger.debug "[TRANSFORM] Added transcendence level: #{trans}"
+        end
+
+        weapon
+      end
+
+      def transform_awakening(param)
+        return {} unless param['arousal']&.[]('is_arousal_weapon')
+
+        Rails.logger.debug "[TRANSFORM] Processing weapon awakening"
+        {
+          awakening: {
+            type: param['arousal']['form_name'],
+            lvl: param['arousal']['level']
+          }
+        }
+      end
+
+      def transform_ax_skills(param)
+        augments = param['augment_skill_info']
+        return {} unless augments&.first&.any?
+
+        Rails.logger.debug "[TRANSFORM] Processing AX skills"
+        ax = []
+        augments.first.each_value do |augment|
+          ax_skill = {
+            id: augment['skill_id'].to_s,
+            val: augment['show_value']
+          }
+          ax << ax_skill
+          Rails.logger.debug "[TRANSFORM] Added AX skill: #{ax_skill}"
+        end
+
+        { ax: ax }
+      end
+
+      def transform_weapon_keys(weapon_data)
+        Rails.logger.debug "[TRANSFORM] Processing weapon keys"
+        keys = []
+
+        # Add weapon keys if they exist
+        ['skill1', 'skill2', 'skill3'].each do |skill_key|
+          if weapon_data[skill_key]&.[]('id')
+            keys << weapon_data[skill_key]['id']
+            Rails.logger.debug "[TRANSFORM] Added weapon key: #{weapon_data[skill_key]['id']}"
+          end
+        end
+
+        keys.any? ? { keys: keys } : {}
+      end
+
+      def calculate_uncap_level(level)
+        return 0 unless level
+        UNCAP_LEVELS.count { |cutoff| level.to_i > cutoff }
+      end
+
+      def calculate_transcendence_level(level)
+        return 1 unless level
+        1 + TRANSCENDENCE_LEVELS.count { |cutoff| level.to_i > cutoff }
+      end
+    end
+  end
+end