Shadow Gate King, Never-Dying

You can't cast this spell from your hand.

Whenever Shadow Gate King, Never-Dying dies, return it to the battlefield tapped.

Whenever you cast a Skeleton spell or a Skeleton enters the battlefield under your control, put a +1/+1 counter on Shadow Gate King, Never-Dying.

Counters remain on Shadow Gate King, Never-Dying as it moves to any zone other than a player's hand or library.