Invoke

Invoke is a common Necrobinder skill that provides Summon effects to build up Osty's HP pool. As a reliable, low-cost way to reinforce your skeletal companion, Invoke is the backbone of the Osty/Summon archetype.

Invoke pairs with Poke, Flatten, and Rattle, which need Osty alive to deal their full damage. Grave Warden provides additional Summon effects alongside defensive utility. Sacrifice converts the HP built by Invoke into massive Block. Combined with Bound Phylactery's passive Summon each turn, Invoke keeps Osty healthy through even the most punishing encounters.

Invoke is essential in the early game when the Necrobinder's other Summon options are limited. Against aggressive bosses like Vantom that threaten to kill Osty quickly, Invoke's cheap Summon keeps your defensive buffer active. In the late game, Invoke may be outclassed by higher-Summon cards, but its low cost keeps it relevant in Energy-tight turns.