Specifically, what would happen if I drank a mix of Rockstar, Gatorade, Red Bull, Coffee, & Cocaine?!

death!

The Rockstar, Gatorade, Red Bull, and coffee probably wouldn't cause too much harm. Maybe a headache/stomach ache from all the caffeine/sugar, depending on how much of them you plan on consuming.
I would skip the cocaine though. That's what could turn a bad idea for cocktail into a dangerous idea for a cocktail.

That is a chemical disaster waiting to happen. That mixture could cause any number of things, from instant death, to puking your guts out, to a coma. Don't do it man. It's just an idiotic idea. And cocaine is never a good idea.

you'd get Four Loko. but dont mix pop rocks in that **** or you'll ******* die bro.

ive been drunk more times then i can count. cuz i suck at counting. cuz im drunk.
wait, what?

You may become the "all-being." Master of time, space, and dimension.

Your body would probably go into a super dooper crash!

You'd look like a moron to all of those who know what a stupid dare sounds like.