yeah, the tricolor slots are pretty lame.
i did some quick testing with all possible combinations of talismans and i have a feeling that you will be forced to chose one "school" rather than 2R 2G 2B.1+1+1 and Assasin set is useless. (EDIT: tested in GOD for damage and in PONR for beneficial effects removal)
unsharded Rending split hardly ever triggers the removal (yes,only removes from the target if it ever triggers) and it dealt around 3x700 damage even with 2800atk from 2 strength sets. shards up the damage by 70%, so it might actually do some damage then.
it's better to go with magic until fully sharded i guess...
also his special does about 2K each dmg and doesn't significantly increase with red talismans where magic damage did increase with holy sets quite a bit.
not sure what to think about him yet....