Frenzy mana cost
When activating Frenzy, it deducts the mana cost for initializing the skill as well as an additional 40 mana already (140 total).
Tooltip description makes it sound like it should be an initial 100 and then every further second, an additional 40. The upkeep cost overall seems fine, just possibly added to the initial cost by mistake.
Didn't want to edit the other Frenzy bug report since it was already assigned.