Beast of Prey buff
In its current state, having it only activate during bloodlust one makes it virtually ineffective simply by virtue of it taking far too long to activate. You can also lose it (even before you have it) way too easily due to poor chase detection or simply by breaking a pallet. Most experienced killers can also accomplish the same effect by moon-walking but it requires you to lose sight of your target and go for blind hits.
The perk should just remove the red stain entirely. I think even then I'm not sure I would use it even then since the effect is just not that powerful. It's also completely negated by certain wall types (holes or just short walls-- hell even windows negate it). At least if it was absent all of the time it could aid certain stealth killers who run reduced terror radius builds (like Myers who run the rabbit add-on and M&A in tier two).
I like the concept of messing with the red stain and making mind games easier. At least this change will make it a bit more attractive.