Sorry, didn't think that through. What I'm actually thinking of is a nature/holy mage, interventioning Felella to cast nullify on whatever creature the opponent wants to DI. Then you'll have a bit more time to setup, so when the nullify is removed, you'll be ready for whatever creature is sent over to you. Or better yet, you could get the enemy to waste their DI, then DI yourself right over to the enemy and start laying the hurt on them while their big bulky creature is all the way across the arena from both of you.