unless your top dog post merge, you won't like it... even if you are top dog, once Ryoka does what it does... you probably won't like it near as much...
Ryoka is not as bad as ES. But for Ryoka, there are only 5 enemies per round, so if you have a lot of people, you may not get to attack for a round or 2 since others already killed the ryoka. For ES, they reset to level 30 and will die in 1 hit.