1 of the reasons combo powers didn't use power remains me of the jackhammer days, and of course the spamming of 1 burst power with no cooldown. It seems like either the power cost is too much or the trolls are dumping low numbers or BOTH. Somethings going on 3 to 4 trolls vs dps power comsumption.
Here is the longer version of the vid, not only does it show the problem with HL and combo powers all together (comboing should not cost power) but it also shows Crappy running his Rage loadout/rotation which is also power intensive. It serves as a great comparison as to how Hard Light was burning thru power compared to doing the same thing with Rage, despite having sufficient power running a power hungry rotation. A gauge if you will. Rage melee Tests after Hard Light Tests in video.
