Beslanki, The Empty Void

{t}, add {w}{u}{b}{r}{g} to you mana pool
Sentience
(Each time you cast a spell with a target, you put one Sanity
Counter onto Beslanki, The Empty Void.
When this card gains 10 Sanity Counters, you may pay {5} to transform
This card into a 7/15 creature with defender.)