Ultimate Ability Idea For A Tank/Support

I just thought of a really cool ability for a tank or support, probably an ult that lasts for 2.5 seconds. Martyr: all projectiles that pass within y units of you hit you instead of their original target and deal x% more damage. Additionally, cc affects from projectiles last x% longer I think x would be around 10-20% but I'm not sure on y. The idea of it is that you can tank a lot of high damage projectiles for your team and probably die because of it, essentially sacrificing yourself so the team lives. Or you can tank a lot of cc so your team can keep fighting but you are left exposed and unable to help further in the fight for a while, which might get you killed.

Feedback is appreciated.