Quote Originally Posted by Nothv13 View Post
I struggled with the same issue until I just started following the ability that glows, it leads you through all the combos, even highlighting to use the buff abilities that have the lower time remaining so you refresh it instead of the one with more time remaining.
Slight correction, the second step highlight does not track your attack or speed buff, it instead leads you to the correct final step so that you can get the buffed final action without issue.

You can test this yourself, if you start with the attack buff, doing the full combo, then use the Dreadwinder combo, starting with the speed buff, then the attack buff, then, when you next get to the second step, you will find your attack button is highlighted, despite the speed buff having less on it's timer.

As for the actual combo enders themselves, they alternate between flank and rear positionals. Attack buff takes you to flank, speed takes you to rear. After a flank combo, you will use the same fang for your rear combo. Once you use a rear combo, you will always use the opposite fang.