Decrepify is being destroyed by Unbreakable.
At very least it should stop in front of him, as with Orianna's Ball.
Although based on Unbreakable's wording, it should not interact with Beatrice at all. Unbreakable only intercepts things that can hit enemy champions, and Beatrice doesn't do anything except fly to the target location - much like Ashe's Hawkshot.
Serevas1 votesNo Braum's unbreakable stops projectiles, the initial sending of the bird out is a projectile, it acts properly.
Orianna ball isn't destroyed because it's literally 100% integral to her kit, and to destroy it would break the champion.
Eeyore1 votesNope, his shield only intercepts projectiles that could have hit him in the first place.
It doesn't block Hawk Shot or Prismatic Barrier.
Wind Wall will block everything, not Unbreakable.
And your logic doesn't hold. Orianna's E is "destroyed" if it hits Unbreakable, causing the ball to snap back to her. There is no reason why her Q should remain in front of Braum, except that the designer decided to implement an exception.
Serevas1 votesACTIVE: Braum raises his shield in the target direction, creating a barrier that intercepts incoming non-turret enemy projectiles and reduces the damage he takes through the shield. The first instance of damage blocked by his shield is negated completely.
Eeyore1 votesProjectiles that cannot hit Braum or his allies (such as an enemy Prismatic Barrier) will not be intercepted. [1]
See, I can quote the Wikia too. I mean, I'm not even sure if it counts as quoting when I wrote most of Braum's page. I'm not even sure what you're trying to prove, either. Regardless of what it says in the tooltip I am still correct that Hawk Shot and Prismatic Barrier aren't blocked - you could test these yourself in game.
Either the bug is that Beatrice is being destroyed when she should be dropped to the ground early like Saplings and The Ball (or even just permitted to pass, like Wolf and Tibbers); or the bug is that nothing happens to Braum when he intercepts her. At the moment she just winks out of existence and Braum doesn't even take damage (/negate damage) and get slowed.
Serevas1 votesDoesn't that in and of itself explain to you why Beatrice interacts, but the other two do not? Beatrice does interact albeit not until arrival.
I'm uncertain of all the interactions, but if Saplings and the ball act that way perhaps you're right and the bird should stop just before. Honestly this is just something I'm going to chalk up to inconsistent spaghetti coding.