Don't mind me, I just want to comment something I've read in the Type-moon wiki just recently. Apparently, Japanese (or Eastern?) Heroic Spirit can't be summoned in Fuyuki grail war, and only Western Heroic Spirit are allowed, due to some kind of restriction when the system was made. Sasaki's(Assassin) summoning was an anomaly in the system due to Caster being his summoner. Again, I'm not sure if this information is accurate. I've only read this from the wiki. Thanks for the chapter, author.