Ahza'rhyl, the Chronoform

Delirium —Ahza'rhyl, the Chronoform has indestructible as long as there are four or more card types among cards in your graveyard.

Whenever Ahza'rhyl, the Chronoform enters or attacks,
you may sacrifice another creature. When you do, destroy target creature an opponent controls. It's controller may search their library for a basic land card, put it onto the battlefield, then shuffle.

Artifacts and nonbasic lands enter tapped unless their controller mills 2.