I agree with Furgin the Warrior about Sword of the Anamist, and deaddman9 about
wall of roots. The only other wurm I'd suggest would be a 1 or 2 of
Panglacial Wurm since you have so much library search already, you could pull them into play while searching up lands when it's late in the game and you have plenty of mana available. I hope that's helpful!