New raid or dungeon boss idea!

So I had an idea where the final boss becomes invulnerable and starts casting a spell which results in an enrage and a wipe. This would roughly be around the same amount of time as ravana or Bismark's enrage timer. The boss is surrounded by 4 subtly different adds that have to be killed in a specific order. They only aggro once attacked so you're not mobbed by them. Until they are attacked they help the boss cast his enrage. So the faster you kill them the the slower his cast. Each add has its own special mechanic that must be dealt with. Once they are done the boss becomes vulnerable and starts attack while still casting the enrage. From that point it is a burn fight. I think this would work best as an ex trail.

Any suggestions or comments? Also I really want the devs to see this cause I think it would be epic!

Sounds similar to a4s.