I'm a little cautious when it comes to combos because there is a very tricky design challenge involved with them. When you have combos in your game, the game probably encourages you to use them. This means you may want to finish your combo no matter what instead of responding to enemy action. This is because the benefits from completing the combo often outweigh the penalty from your lack of reaction to an enemy's move. This leads to you simply repeating the same combo over and over with little interaction with the opponent.

Warhammer Online had a couple classes based on combos (Black Orc and Swordmaster) where your abilities were organized into three tiers with the second tier only being available after a first tier attack and the third tier available after a second tier attack. I never tried Swordmaster but I did not like Black Orc because you'd constantly cycle through your combos with little thought to what was actually going on. Even if you wanted to respond, you couldn't because you had to do irrelevant move X before you could use the correct response Z. Also, the final tier moves were so much more potent than the lower tier ones that you really just wanted to climb the ladder over and over as quickly as possible to get as many tier three ability uses as possible.