Bloodthirsty Explorer

When Bloodthirsty Explorer enters the battlefield link. (Put a colorless Chains land artifact token onto the battlefield, it has "{t}: add {c}" and "chains don't untap during your untap step")
{1}{b}, sacrifice a chain : Bloodthirsty Explorer gains lifelink until end of turn.
Whenever you sacrifice a land put a +1/+1 counter on Bloodthirsty Explorer.