I have a question
Now didn't imu defeat dory and brogy when he was able to subdue them?
Clearly imu can kill them but he doesn't do it
Rocks needed the help of 5 other people and they did one of their strongest attacks and imu didn't take any damage
Imu low diff rocks
Imu did indeed could defeat Rocks anytime he/she wants.
But about the Domi reversi part,
Its just like how Shamrock attacking injured Loki, Gunko even said Shamrock didn't need to dirty his own hands to a filth like Loki, hence why he use Cerberus to deal the "final blow".
In Imu case, its kinda like that one maniac or Doffy if u want One piece char, who enjoy seeing people getting murked by their loved ones. Who think wouldn't it better if i didn't even try, but can use the strongest people in here to murked everybody.