diff --git a/app/logical/source/url/fantia.rb b/app/logical/source/url/fantia.rb
index b4b163efe..7253628f9 100644
--- a/app/logical/source/url/fantia.rb
+++ b/app/logical/source/url/fantia.rb
@@ -6,7 +6,7 @@
 # https://fantia.jp/profiles/tus_2n9n0fm05fizg
 
 class Source::URL::Fantia < Source::URL
-  attr_reader :full_image_url
+  attr_reader :full_image_url, :fanclub_id, :username, :post_id, :product_id
 
   def self.match?(url)
     url.domain == "fantia.jp"
diff --git a/app/logical/source/url/twitter.rb b/app/logical/source/url/twitter.rb
index be3042a3c..57cf3db6f 100644
--- a/app/logical/source/url/twitter.rb
+++ b/app/logical/source/url/twitter.rb
@@ -88,15 +88,15 @@ class Source::URL::Twitter < Source::URL
   end
 
   def image_url?
-    orig_image_url.present?
+    domain == "twimg.com"
   end
 
   # https://pbs.twimg.com/media/EBGbJe_U8AA4Ekb.jpg:orig
   # https://pbs.twimg.com/tweet_video_thumb/ETkN_L3X0AMy1aT.jpg:orig
   # https://pbs.twimg.com/ext_tw_video_thumb/1243725361986375680/pu/img/JDA7g7lcw7wK-PIv.jpg:orig
   # https://pbs.twimg.com/amplify_video_thumb/1215590775364259840/img/lolCkEEioFZTb5dl.jpg:orig
-  def orig_image_url
-    return nil unless @file_path.present?
+  def full_image_url
+    return to_s unless @file_path.present?
     "#{site}/#{@file_path}:orig"
   end
 
diff --git a/app/logical/sources/strategies/nico_seiga.rb b/app/logical/sources/strategies/nico_seiga.rb
index 31c1e0f26..d56609574 100644
--- a/app/logical/sources/strategies/nico_seiga.rb
+++ b/app/logical/sources/strategies/nico_seiga.rb
@@ -40,7 +40,7 @@ module Sources
       end
 
       def profile_url
-        "https://seiga.nicovideo.jp/user/illust/#{api_client.user_id}" if api_client.user_id.present?
+        "https://seiga.nicovideo.jp/user/illust/#{api_client.user_id}" if api_client&.user_id.present?
       end
 
       def artist_name
diff --git a/app/logical/sources/strategies/null.rb b/app/logical/sources/strategies/null.rb
index 64ff636df..aa1b45938 100644
--- a/app/logical/sources/strategies/null.rb
+++ b/app/logical/sources/strategies/null.rb
@@ -15,6 +15,10 @@ module Sources
         url
       end
 
+      def artists
+        ArtistFinder.find_artists(url)
+      end
+
       def normalize_for_source
         case url
         when %r{\Ahttp://www\.karabako\.net/images(?:ub)?/karabako_(\d+)(?:_\d+)?\.}i
diff --git a/app/logical/sources/strategies/twitter.rb b/app/logical/sources/strategies/twitter.rb
index 1f0bf06b2..5ea6f37ff 100644
--- a/app/logical/sources/strategies/twitter.rb
+++ b/app/logical/sources/strategies/twitter.rb
@@ -30,7 +30,7 @@ module Sources::Strategies
     def image_urls
       # https://pbs.twimg.com/media/EBGbJe_U8AA4Ekb.jpg:orig
       if parsed_url.image_url?
-        [parsed_url.orig_image_url]
+        [parsed_url.full_image_url]
       elsif api_response.present?
         api_response.dig(:extended_entities, :media).to_a.map do |media|
           if media[:type] == "photo"
@@ -43,7 +43,7 @@ module Sources::Strategies
           end
         end
       else
-        [url]
+        []
       end
     end