In chapter 98 of Chainsaw Man part 2, it was revealed that the War Devil saved Asa from death. The new villain seemed to have a grudge against Chainsaw Man, most likely the same way as the other Four Horsemen.
What are the War Devil’s Powers?
It wasn’t a surprise that the War Devil has supernatural abilities, after all, it was considered a deadly devil. One of its abilities is the flesh weapon wherein it can create deadly weapons made from human flesh as its material. To do this, the War Devil must touch its desired material. It has created 2 flesh weapons so far: Tanaka Spinal Cord Sword, a crooked sword made from Tanak’s head and spinal cord, and Flesh Hand Grenade, a hand grenade made from the arm of the Class President. The War Devil can also bestow contracts upon humans, and of course, it comes with a price. Asa and the War Devil created a contract for her to be reborn that benefited her and the War Devil as he used her body as a vessel. It can also restore its health by simply consuming blood. To make things worse, it can revive in hell, making it immortal. The War Devil also possesses enhanced speed, which allows it to easily dodge attacks and jump around, and enhanced strength to easily carry objects without a sweat. Asa Mitaka has displayed great swordsmanship ever since The War Devil possessed her. She was able to defeat the Class President with her sword easily. One factor that made the War Devil powerful is that it is confident and prideful. It is aware of its abilities and believes that all enemies, aside from Chainsaw Man, are just warm-ups. It vowed to take the Nuclear Weapons from Chainsaw Man and until these two have a fight off, it is still hard to determine if War Devil will achieve its mission.