The skill description makes it seem to as if frenzy runed with sidearm will give a 25% chance of throwing a piercing axe on top of the attack. Is this true or am I misunderstanding something?
Example of what I mean: Assume I am fighting one single enemy. If the piercing axe procs, will that attack deal 220% weapon damage to my enemy (110% from the normal attack and 110% from the piercing axe)?
If this is true, then what is the point of the maniac rune? The maniac rune will boost dps by an additional 20% of weapon damage (but only when at full frenzy stacks). But the sidearm rune boosts dps by 25% of weapon damage (and is not dependent on having full frenzy stacks).