Scour for Scrap

Modal tutoring at instant speed is the whole pitch, and the two halves address the two places an artifact deck loses its threads: the library and the graveyard. The "one or both" clause is where the card earns its four mana. In a single cast you can dig for the missing piece and, in the same breath, buy back the one that already died, reloading two axes of a plan that was falling apart. Instant timing is doing quiet structural work: hold it up so you can rebuild on the opponent's turn once an artifact has hit the graveyard, rebuilding in reaction rather than telegraphing your tutor on your own turn. The cost of the flexibility is that neither half puts anything onto the battlefield. This finds and returns cards to hand, so you still owe the mana to recast whatever you retrieved, which keeps it a setup spell rather than a tempo swing. The lineage is blue artifact-fetch effects that traded rate for card selection; the recursion clause is what this design adds on top, letting a deck treat its graveyard as a second library and never truly run out of the specific piece it needs.