Cthulhu was clearly pissed to have its plan ruined entirely.
Whatever it did earlier was to try and limit Bai's movements. He had tried to drag Bai into his territory completely.
Never had he thought that Bai would manage to pull off something like that by circumventing the prohibition on flying in R'lyeh.
Moreover, Bai was hidden in the blood-colored clouds in the sky currently; he had hidden himself from Cthulhu entirely.
Under Cthulhu's control, the water that had flooded the entire big city was still rising.
Countless whirlwinds rushed out of the water like tentacles and attacked the blood-colored clouds in the sky.
Facing such a situation, Cthulhu had no other options but to attack. He decisively chose to compete with Bai to see who would have their Dominator Power drained first.
R'lyeh was its Kingdom. In one's Kingdom, the draining of its Dominator Power was less than one-tenth compared to in the outside world.
