Or this could've been named Shin Akuma vs. Abyss.
Or better yet CFJ Akuma vs. Abyss to make this closer.
Abyss simply rains countless epic-sized meteors on Akuma until he's dead. Akuma can manage to destroy some for a while (and that's being generous).
If he decides to fight Abyss head on, he would either get compressed by one of Abyss' space-compressing attacks, or get torn a new one by the Irkalla (Zasalamel's Kafziel, in its altered form after being corrupted by the same energies that formed Abyss).