A Hippogriff is a 2 INT magical beast. It doesn't speak a regular language and it's immune to Speak with Animal. While I don't agree with most of what Talic ruled , if Leaf can't communicate* with it, he can't make it not attack.Leaf will have to get a Mindlink tatoo for the next battle.Edit: Mindlink has an Int 3 lower bound.
If you'd like to call in Kyeudo for GM Override, you are welcome to. I was feeling selfish for delaying the match this long.
We should get a ref to summarize the results of Leaf's turn (for those who can observe it), but yes, it's your turn.
*'Communicate' has been defined far more strictly than I had anticipated.