I mean it's kinda obvious it's him and he's colluding with the human kingdom.9 out of 10 it was that shitty king who wanted her killed.
You say that like that's a bad thing.God I hate early and mid story tournament arcs. Unless the story is centered around a tournament, tournament arcs are just a plot pause button. They are cliche', drag on, and make all the main plot points stall until the tournament concludes.