I am in the Kislev sewers and I have Fei at level 52 and Citan at level 50. I was just wondering if these are good levels to move on in the game or do I need to continue to build their skill level up some more?

err it's been a long time since I've played this game.. Kislev sewers, you mean that prison episode, right?

when I first beat this game my characters were at 60-65 level. I think yours 're even overpowered .

What really matters is learning the battle techniques. The levels you have now you could comfortably beat the game with, provided that you learnt the battle skills.

Why?

Because the more skills you learn for your character, the more skills you can use in your gears. Although the charge system is a little agonising, some of the more advanced killer blows for your gears pretty much break the game.

They are also useful for non gear battles, particularly odd number ones that let you build stock up (well, if you like that sort of thing, I just like to see the blows in fast forward).

yeah, but you can't learn the final deathblows until you're lvl 60 or something. not that you have to learn them all, but Fei's final deathblows are uber strong.

and in dungeons where you can't use Gears exp levels matter in this game.