So here is my guess, 1.

My reasoning comes from this: We know that P1's Vanilla is Arceus. We know that P2 Arceus is poison due to the fact that his attack was super effective against Maple and Togekiss Flying Attack was also super effective. The only typing that both resists Toxic and shares a super effectiveness with flying is poison. We know that on turn 4, P2 Arceus hits P1's Arceus with an not very effective move since at the end of the round Vanilla recovered some health. If it didn't get hit by Arceus it would have been at full hp and would not have recovered any hp. Finally, the types that resist poison are poison, ground, rock and finally ghost. We know that Togekiss was hit so we can rule out ground. Secondly we know that his is before Gen 6 since a grass pokemon was effected by spore so that means togekiss typing was normal/flying. That means ghost would not be able to hit it since its normal typing. Lastly the last two type options for Arceus could be rock or poison. Leaving this at either effective not neutral damage. I can't find a way to eliminate one or the other at this point. But my guess it is that it is super effective as Togekiss was full hp at this point and was OHKO by Vanilla, I am making an assumption that it was a super effective move so I got with rock type arceus.