Sapphire Collector

Cheap and free spells can cash this in immediately; Mox Sapphire plus prowess is a strong, likely regular engine payoff for Izzet spell decks.

Could be wrong if If removal or insufficient free spells makes the trigger unreliable, it is merely a slow 3/3; a new combo shell could also exceed this estimate.

Legacy's free spells make the Mox trigger accessible, but a vulnerable three-mana creature must overcome Daze, Force of Will, and efficient removal.

Could be wrong if A compact spell-combo shell could exploit multiple Collector copies far better than existing tempo lists.

UR spellslinger decks can readily unlock a Mox and later rebuy spells; it is potent, but restricted to red, spell-heavy decks.

Could be wrong if Faster mana and recursion may be preferred, while multiplayer removal can prevent the trigger.

A 3/3 prowess creature is solid, while a spells-heavy UR deck gains a Mox and costly late spell recursion; both rewards need setup and blue mana.

Could be wrong if Unknown spell density, UR support, and removal determine whether its rewards outweigh the baseline 3/3 prowess body.