Zell, Hand of the Pale Horizon

Integrate (Whenever a permanent becomes attached
to this creature, you may exile that permanent. If you
do, put X +1/+1 counters on this creature, where X is
the exiled permanent's mana value.)
{1}{c}{c}: Return target Aura or Equipment card
exiled with Zell, Hand of the Pale Horizon to the
battlefield attached to Zell.
Other colorless creatures you control get +X/+X,
where X is the number of permanents attached
to Zell, Hand of the Pale Horizon.