Eh...taking sentinel isn't really going to increase your damage by a significant amount. At least compared to going straight bloodrager.
Losing your spell caster progression and bloodline progression are pretty big hits to your power.
Also destoryer's blessing will only mitigate some rage usage. Remember it only works once per round, so at best all it does is keep you from losing that round of rage you were in when you performed the sunder.
Horn of the Criosphinx is okay, but you're better off in general with just trying to get full attacks. It's x2 strength damage instead of 1.5, but only when charging. Which means it's only good for one attack. It's ok, but I would probably choose a different feat. Also, even if you pick up rage powers using primalist based on other rulings about how pounce interacts with things it would still only apply to one attack after the charge.
What does Sentinel actually give you?
You have to wield your deity's favored weapon to get a bonus, and assuming you're okay with worshipping pretty much only Gorum it works out okay. But not everyone wants to be shoehorned into worshipping one god. Otherwise, weapon choices are lackluster. But for it you can get up to a +4 to attack and damage. Not bad.
But that's basically the only really good thing the whole class gives you. I just don't see it.
Leadership. Bonuses to initiative when wielding your deities favored weapon. Damage reduction 10/alignment. Diehard, free cure critical wounds, bonus feats, sentinel levels stack with fighter for feat prerequisites, bonuses to resist divine spells, bonus to cmb and cmd with greatsword. I don't think it's a bad tradeoff. Yeah, you lose SOME abilities, but not much. And it may not be as flavorful as straight bloodrager, but I dunno, I think it is damaging as all hell.
And most guys will only ever benefit from one attack on the charge, the exception being the barbs who get pounce, and the shape shifters who choose an animal form with pounce. I'm not sure of any other way to really get it.
Leadership is a mixed bag. You could tell me all you want that you get Leadership as a bonus feat, as a GM I'm going to tell you that you get a different feat in it's place. I expect many GMs would agree with me, or have some sort of restrictions in place on Leadership. It's all nice and shiny, but don't expect that to work as well as you would like.
And if your GM actually allows it, then it's something you could take as a straight bloodrager anyways.
Bonus to initiative is meh. You're melee, going first isn't all that important. In fact, letting the enemy move to you so you can get a full attack can actually be much better than have to use your move action to do so. The init bonus isn't bad, but it isn't particularly great either.
The DR is alright, but you're getting at at Sentinel 10, character level 15. It's DR, so it's nice to have but it can also be bypassed with an align weapon spell, which is 2nd level. Also, it is bypassed by +5 weapon. Which are probably going to be popular by the time you reach this level. Maybe not everyone has them, but they shouldn't be non-existant either. Again, it's decent but still not that outstanding to me.
Diehard, the free cure, the bonus to CMB/CMD, and the bonus against divine spell saves are all just so-so. None of it's bad, but none of it's great.
What you gain, in terms of damage which is what you seem to be focused on, is +4 sacred/profane damage, and the ability to pick up Weapon Spec and Greater Weapon Spec, which would add another 4 damage.
However, you will lose a lot of bloodrager stuff to get these things. Lets assume a typical game, which will end somewhere between levels 13 (PFS) and 15 for Adventure paths. You're only a 5th level bloodrager.
Thats only 12+con modifier rounds of rage per day. Sure you can use your destroyer's blessing to preserve your rounds, but you can only stretch it so far. You really wont be able to make any use of Raging Brutality, it will burn up 3 extra rounds of rage each time you do. What if you fail on the sunder? What if you're fighting animals or creatures without gear? Are you going to not rage while fighting them?
You miss out on bloodragers DR/-. You also miss out on greater bloodrage. You miss out getting more than 1 spell slot or high spells known. You miss the high level bloodline abilities which depending on the bloodline are exceptional. Bloodrager gets several bonus feats as well, though different lists. But many are solid.
And if you had went Abyssal bloodrager you could be large, have energy resistances, get strength bonuses which will help even further with 1.5 strength with two handed weapons.
You might come out a few points ahead in damage because of the access to Weapon Spec and Greater Weapon Spec, but what you give up just is in no way worth it to me.
Also, arcane strike and blooded arcane strike are probably worthless feats since arcane strikes damage is based on your caster level which will stop at 5. That's +2 damage that youre spending two feats on so you don't have to use a swift action each round to perform. You're literally better off taking weapon spec and greater weapon spec because that's +4 damage and also doesn't require an action.
Yeah, I was just trying to help you analyze what you gain versus what you lose and how that affects the overall character strength.
Sentinel adds some interesting different abilities, but it doesn't build on itself so well. For any character with spell casting it hurts since that is usually a decent part of the class' power. Even for 4th spell level casters your still losing a big bunch of progression and versatility. On a bloodrager, you're losing a pretty good deal of buffing potential.
If you were going to go bloodrager sentinel, it would be almost the same as if you just went barbarian sentinel.
I'm not sure what class goes well with Sentinel, but if your goal is to optimize a character, I don't think combining Bloodrager and Sentinel makes a stronger character than just making a striaght Bloodrager.