Underworld Breach gives each nonland card in your graveyard escape while the enchantment remains in play. You can cast those cards by paying their mana costs and exiling three other cards from the graveyard for each cast. That turns a stocked graveyard into access to interaction, tutors, mana sources, and potential finishing sequences.
Lion’s Eye Diamond and Brain Freeze form a well-known engine with Breach. The Diamond can supply mana, while Brain Freeze mills cards to replenish escape material and builds toward milling opponents. Repeated casts increase storm count, but the sequence needs enough starting resources and graveyard fuel to function. Each escaped card consumes three other cards, so simply controlling Breach is not enough to start an unrestricted loop.
A less elaborate use is replaying a removal spell or tutor that the current turn needs. Cheap cantrips and rituals can help extend that turn, especially when they replace resources or generate more mana than they cost. Ruby Medallion can reduce generic costs on red spells, although it does not reduce the number of cards that escape requires you to exile.
Breach is sacrificed at the beginning of the end step, making it an engine to use promptly. Normal timing restrictions still apply, and lands cannot be played through its escape permission. Graveyard removal can interrupt the plan or remove needed fuel. Sequence your plays around the cards that must remain available and treat the graveyard as a limited resource, choosing whether a short value turn or a committed combo attempt is the better use.
