If you choose the skill point; assuming you have all the other ones, you can win the fight with Valravn WITHOUT Brianna's help.
If you choose the power point and DON'T challenge Ella; you can get the Kenny follow feelings corruption point which leads to a few extra scenes early on, while still being able to sacrifice some other corruption choices (my personal preference).
KEEP IN MIND HOWEVER: That if you choose the power point but DO NOT pick the Horn, you will be saved by Brianna during the Valravn fight. The alternative would be gaining the skill point and NOT picking the Horn, however it's at the cost of missing the Kenny feelings and a few (based on some choices) missed early on corruption dialogue/choices/lore.
This is a long-ish read if you're interested in my approach to this game:
My personal goal is to be a Monstrous Harem Master. I kill those who get in my way (minus women i.e Danica and for sure Ella regardless in the future, she's just too interesting no matter how you play) and I try to sleep with pretty much everything with a pulse (minus female MC scenes, save for the Futa; dick girl power!). To be Monstrous, I try to get all the corruption points I can with lore, while still trying to keep every female alive and well looked after.
Examples being:
1. I spared Danica (Corruption loss)
2. Killed Bailey at her request (I believe she was going to die regardless, but you can still get corruption if you kill her at her request; just not as much as if you were to kill her early)
3. I spared Erik (Liz's sponsor) in hopes of him taking care of Liz AND Amber's Swimming career AND Lucy his secretary for potential future scenes (though I'm 75% positive Weird World is done with her, but you never know).
4. I kill pretty everyone else, and react negatively to negative males (i.e Jake, Dexter, Deryl, Xanthe, all of H.E.R.O execs minus the females of course, etc. etc.)
5. Not counting all the things I've mentioned, I take all the corruption I can get, killing the farmer, Emily's Dad's Blackmailers, public opinion down and government opinion down whenever possible, kill the inmate bully, kill the mall cops, you get the picture, all of which are pretty much justified save for the farmer.
6. Most detrimental choice possibly; I took the Eye over the Horn. There was something about an Ancient Monster's memories that definitely points towars corruption points AND power, it's just a waiting game. As the Shopkeeper says with the Horn that it's the straight forward approach, something tells me that Eye is going to be worth the Brianna save.
I may change my decisions in another run, i.e not doing the Kenny thing and doing the skill point instead just for being a bad ass, but Brianna's save was kinda out of a movie it was so good. And no one really comments negatively on it, not even Nicolette. If anything, I gander beating it yourself will only boost public opinion which I am not for, so I'll probably stay with the choice. Sorry this was long, hope it helps if you're going my route.