New hero skills for OOTM

[Jaedar]

What/where are they?

I couldn't see anything in the skill trees... There are some new ones in the skill tree if I start the arena campaign, but the blurb states there are new ones for OOTM as well. Are they hidden, or is it some sort of weird bug?

[Rhygadon]

They're given as quest rewards.

[DGDobrev]

There are also a number of skills in the skill trees - replacing ones that were slightly underpowered or less used. For example, warrior gets a skills that adds to all resistances and such :)