Blood Weapon / other DRK suggestions:

[Nektulos-Tuor]

Because what do you define as a boss? How would the game know? How would it restrict it? Is a dungeon mini boss a boss? Yes I'd want to use it on one of those as there's trash right after and I might be tapped out and it would get me to the next pull faster. Is a hunt a boss? Yes I want to use it on one of those as I might go right back into farming mobs around it after. Is zombie dragon in CT a boss? He dies 3 times yes I'd want to use it on him to get my mp back up. It's a stupid restriction. You just need to learn to use it properly and not expect the game to do it for you. The 15% on mercy stroke is a restriction not a benefit, it's there because it does damage, if it was unrestricted you could open with it and spam it throughout the fight for an extra 200 potency attack.

Bosses in this game, are usually surrounded by an area or arena. They also usually drop a chest afterwards. Usually are found in Dungeons and Raids. That fight "the dragon" also has a ton of adds you can use it on. Don't be a baby, this is a really good change and actually a good idea.