I finished off my counts-as Mepheston a few weeks ago. I really didn't like the current metal model so I took a Sanguinary Guard model and added on a grey knight rear torso for a psychic hood. The large two handed sword (and his mind power!) should show the Strength 10 beasting and the backpack will show off his other power...
I didn't want a standout blue body with my army (which is mostly an armoured core) so I stuck with a blue shoulder pad.
The only thing I wasn't happy with is the face on the leg. I don't even like this part of the model truth be told but the bits order I placed couldn't provide the one I wanted. I suppose you make due with what you have.
I have since fixed the gem on his hilt. The white balance is all messed up in this one but doesn't affect it too much I guess.
The best part about him is that he replaces my previous librarian models that I was using for Mepheston and boy does he do that well. My painting has significantly improved since this model from 3 years ago (at least I'd like to think) not to mention the new one stands almost twice as tall and deserves to be worth a land raider.
New Meph also dominated the last game I used him (yeah yeah when doesn't he). He destroyed half a chaos squad of traitor marines which allowed the furious assault marines with him to clean up before the traitors could return a swing.