Nyarlathotep, Chaos King

Indestructible
{x}{u}-Nyarlathotep becomes a copy of target
creature with power x or less until end of turn
{3}{r}{r}{t} Gain control of target creature until end
of turn, untap it. It gains haste.
{2}{b}{b}{t} Destroy target creature, its controller
puts the top x cards of their library into their graveyard, where x is that creature's power.
Whenever Nyarlathotep attacks, defending player exiles the top five cards of their library