Smelting Vat

The trick here is the currency conversion: an artifact's mana value becomes the budget for what you dig out, so the ability is only as strong as the fodder you feed it. Sacrifice a two-mana rock and you pull one cheap trinket; sacrifice something fat and expensive and you drop two noncreature artifacts totaling that value straight onto the battlefield, cheating their costs entirely. That downgrade-into-value engine wants a deck built around mid-cost pieces worth trading down, because feeding it a token or a zero-value trinket only ever nets you another zero. The reveal-eight clause is the real texture of the search: you see a wide slice of your deck, keep the two you hit, and bottom everything else. That bottoming is not a hidden cost in the way it looks; the cards you passed over rejoin an unknown library, and you draw from the top regardless, so the loss is opportunity (you saw those pieces and could not afford them this activation), not a self-inflicted disadvantage on future draws. What makes this more than a tutor is the outlet itself: it is a repeatable sacrifice engine first, and its payoff feeds on your library rather than your graveyard. So the deckbuilding question is not what you can recur but what you can afford to melt down, and how much value you can extract from converting one artifact into two smaller ones on your terms, at will.