Asgrad, the Time Warden

Whenever you cast an instant or sorcery
spell, put a charge counter on Asgrad, the
Time Warden. Surveil 1. (Look at the top
card of your library. You may put it in your graveyard.)
{1}{u}{u}, Remove eight charge counters from Asgrad, the Time Warden: Take an extra
turn after this one.