Cousteau, Relentless diver

Islandwalk
When an artifact you control is destroyed
and sent to the graveyard: create a Treasure token.
{t}Sacrifice 15 Treasure tokens:
Search your library for two artifact cards and
exile them.
An opponent chooses one of those cards.
Shuffle that card into your library.
You may cast the other card
without paying its mana cost.