The active skill on Dionysus is to cure then regen for three rounds. The three rounds of regen seems to be bugged.
I have been playing the Tower a lot to test this Titan and the regen only occurs when I apply it to a Titan and the battle goes more than one round, it heals. But, if I defeat the opponent in the same round as the application, no healing. Since it doesn't carry over to the next opponent, it makes the ability almost useless, as half the time they are down in 1.
I still need to test the usefulness in the coliseum.
One fix would be to have it heal upon application.
Personally, with the high cost of ethereals, I feel the ability should be a splash cure and 1 round heal to 3 titian. A combination of Divinictus and Providein.