Eldrath, Mind Delver

Partner, Skulk, lngest
{x}{u}{b}{t}: Target players mills X.
Whenever this card would cause 1 or more
instant or sorceries to move from a library
to a different zone, put X +1/+1 counters
on target creature youcontrol, where X is
the highest Converted Mana Cost among
the instant or sorceries moved.