Talk:Ruler/@comment-33784096-20180710024852/@comment-27971189-20180921183614

Its because Amakusa was summoned through Einzbern act of cheating the summoning system resulting on Grail recognized Amakusa as impartial saint fitting the Ruler container.

Thus, unlike other Ruler, he does have desire to claim the Grail, an attitude which Einzbern needed as they didn't need impartial Ruler but Ruler willing to fight and win.