Phyrexia's Core

A colorless source whose second line quietly turns it into a sacrifice outlet, built for the deck that would rather feed its own artifacts to the graveyard than let an opponent answer them. The colorless mana is the cover charge: this earns a slot as a land first, so the outlet costs you nothing you weren't already paying, which is what separates it from a dedicated sacrifice rig you'd never run in a fair manabase. The life gain is incidental. What the ability sells is a repeatable way to put your own artifacts into the graveyard at instant speed, paying one generic mana and tapping the land each time. That matters whenever an artifact carries a death trigger, a recursion clause, or a body you'd rather see die on your terms than get exiled by removal: sacrificing it gets the permanent to the yard first, and it feeds anything that wants artifacts dying rather than sitting. The cost structure is the brake. Because both abilities demand the tap symbol, the land can either produce mana or sacrifice an artifact in a given turn, not both, and the sacrifice ability still asks for a generic mana from elsewhere in your pool. That friction is why it reads as a value land rather than a combo piece: a colorless source that asks nothing of your color requirements, with an outlet that's pure upside for any build treating its artifacts as resources to be spent.