Well, tbh I have not played this game in a long time but I realized very early that rogues could become brutally strong.
They had a ridiculous amount of free percentage stat bonuses, movement boosts, percentage armor bypass, and percentage debuffs.
That is not including the fact that they had not so bad base stats for that. Basically the only way that they would be balanced is if their gear were weaker. Give them the same stats and everything is boosted by at least 15% in basic attack stats(compounded on each other), much much more in the case of damage skill modifiers.
Most people forget that Critical chance becomes more effective the higher it is and that once you have it all base attack stats (attack speed and damage) become more effective per point. Did I mention free percentage critical modifier?
In terms of attack speed, all special proc weapons become more effective with more attack speed or skills that hit multiple times. (since rogues have on hits anyway it benefits them more)
And then there is dodge. It basically screws over anyone or anything that does not have enough to hit the player. Even 25%(actual dodge chance after hit rate) can be ridiculous since it could potentially dodge a main damage source attack. Speaking of that, the on hit passive debuff was kind of ridiculous as well.
The damage amplification was actually kind of scary. (sucks to be squishy)
Then there is the armor bypass. 35% armor shred for 6 seconds every 10 seconds and a complete armor bypass attack every 6 seconds. (sucks to be a Knight, and the armor bypass made it quite possible to steal bosses)
And passive % healing reduction to top it off (yes it has low chance to proc but who cares when you hit so fast). (Sucks to be a Priest)
The last thing is that movement speed is one of the strongest stats in the game. It does not matter if you are weaker defensively if you can kite away from attacks or get in close easier to do damage. Then there is just the fact that you can get around more conveniently.
Then I looked at other characters and saw that they had mostly base stat bonuses and not percentage. Figures this happened.
The only downfall to rogue is a lack of AoE damage attacks.