Warpath warrior’s fury does not seem to be correctly calculating the mana cost of the channeling.
I have 2 points in Warrior’s Fury, 5 points in Unchained, and 1 point in Reckless Spin.
I have a relic with -3 melee attack mana cost and a primal T8 channel cost affix helm (66%)
With the above, I would expect that after the 10 second cap, my channeling cost would be 18+80-19 = 79. 79*0.34 = 26.9 per second. However, the channel cost goes all the way up to 38.3 per second.
I recently respec’d from Paladin to Voidknight. As a Paladin - I had a similar issue except that instead of going up to 38.3 it went up to 29.6; as if the channel cost capped at 11 seconds instead of 10 - not a huge deal so I never worried about it.
Now after this respec to voidknight; it is inexplicably a lot worse.