Tank Devil

On its own the devil's true shape is never revealed. Once Yoru turns it into weaponry, it manifests as an entirely black left arm standing in for the limb she had lost, wrapped in a clinging glove of dark lace.

Its disposition is never spelled out. Like the Gun Devil, it holds a deep bond with the War Devil, who regards herself as its mother. The instant Yoru cried for rescue while the Chainsaw Devil had her cornered, the Tank Devil smashed out of its holding cell and raced to her side.

When Pochita has Yoru on the brink of defeat during the Aging Devil arc, she recalls her deeper reason for wanting the Chainsaw Devil dead and reaches out by telepathy to the Tank Devil and the Gun Devil alike, pleading for aid. Bursting free from the detention site on the Gulf of Mexico, the Tank Devil joins the Gun Devil on the field, and both convert into arms for Yoru, this one forming her left tank gauntlet. In her later rematch against the Falling Devil she channels its power, loading her right gauntlet with the whole hoard of firepower she has banked and unleashing it all in one burst to seize the upper hand. Its exact abilities stay unclear, yet its raw firepower is immense, enough to punch through the blast door caging it with a single strike.