Tekkit Classic how to kill a person in red matter armor?

Yeah. Then, by your logic, there would be an Abyssal Armor, an Infernal Armor, an Gravity Armor and a Hurricane Armor. Get your facts right before posting, derp.

god damn noob -.- shut up if you dont know what you're talking about

I know that you mean the piece, but to use the spells you need the whole set, so the correct naming would be Gem Armor, not Infernal Armor, since Infernal Armor is just the Chestplate.

To clarify, the whole set is indeed called Gem Armor. The chest piece is the Infernal Chestplate.

HOWEVER COMMA

When you activate the abilities using G or V, it does say "Infernal Movement abilities" and "Infernal Offensive mode" or something very close to that, referring to all of the armor.

So it's an easily explainable miscommunication.

There's a bug with Red Matter and Dark matter. They don't absorb explosion damage so you can kill them in one shot (if you hit a certain part) with a diamond warhammer.

The Chestplate in the Gem armor set is actually CALLED Infernal Armor. It is a chestplate, but that's what it is called.

shut the fuck up, stupid nigger motherfucker

... This guy is very dense. And very late.