Merkava is one of the playable fighters in the game Under Night In-Birth, he's one of the many eldritch creatures that inhabit the Hollow Night known as Voids. Merkava is driven by the instinct to consume existence. Unlike other Voids, however, he is sentient and intelligent, having once been a human until he was consumed by the power of Existence. In this game, he serves an antagonist role as one of Dust of Osiris' to elite minions. In the very beginning of the game, he plunges Shantae into a dark, void-like realm in the middle of her sleep. He bargains to give him her heart in exchange for something that Shantae would seem to have a hard time saying no to... however, saner heads prevail when Shantae denies his bargain, enraging Merkava, threatening her that he will rip her heart out of her and the two do battle, after seemingly losing the fight, he pulls off one last trick and starts consuming Shantae into darkness, only to wake up that it was all crazy nightmare when her friends were at her place in a sleepover to watch the annual Smash Tournament in the midair stadium. Or was it a dream... He's encountered once again near the climax where you get to fight him for real.

He sounds cool and collective, yet cold and cunning. Very much like Infinite, he has a distorted voice. But when he snaps (and boy does he snap on a dime), he starts shouting words with inhuman screeching and howls and starts acting totally insane in the heat of the moment.