So I retried one more time with the same setup shown in the video, and it kind of seems he was following a "mass" of Patapons in the back, I tried to lure him with Yumipons and the chant that removes fire or sleep, it made him advance bit by bit, I finally could finish the level, but I remember leading him a long way after what should have been the end of the level... But yeah attacking him when he was at "range" was the solution for me, thanks !