Quote Originally Posted by Kafrein View Post
I'm not sure why people think these are Delve only? I learned Carcharian Verve in a Wildskeeper Reive. You don't need to get the killing blow or be in the same party/alliance as someone who does like Besieged, I just learned it when the Reive ended.
At the date of the OP, it was only available to learn in Delve as stated in the update that added the spells. The development team said they would look into adding them to Wildskeeper Reives and it was ninja added in the December update.