First things first, I love how you use Kyurem. It's an underrated Pokémon that can (and probably will) cause a lot of pain :)
So, when looking through your threat list, I can see how Jellicent patches up a lot of those weaknesses. Therefore, I second Superpowerdude's suggestion of adding Jellicent.
Jellicent will function as a secondary psychical sponge, and therefore make it easier for Donphan to do the jobs he should fulfill. I'd like to see Donphan changed for a spinner like Tentacrue, or maybe Starmie. However, this would mean an important team member has to fall.
I recommend Jellicent
Be careful with Donphan!