Pfffffffffffft. Grey Knights survive chaos worlds and leave them in absolute disarray and destruction.

Justicar Alaric <3

I'd say Space Wolves too. But then again I'm a little biased as they my favourite Space Marine chapter

What did you say, didn't quite catch that.

The toughest space marine chapter is by far the Rainbow Warriors because they are themed after rainbows.

Lol, the most disappointing thing about the Rainbow Warriors is that they aren't in rainbow armour. They look like Ultramarines w/ the Blue and White. They should at least be Green since they are the Greenpeace Chapter

We have some contenders: Space Wolves, Dark Angels, Blood Angels, Grey Knights, Black Templars, Iron Hands. Iron Hands are a really cool call, they are underrated for sure. Grey Knights of course are awesome.

What about Emperor's Children? They spend all their time practising warfare as art. That's some dedication.

Grey Knights, on account on having Anval Thawn at their side.

Good luck killing a Perpetual.

What is that even supposed to be. Someone trying to be a Deathwing Terminator and a Veteran Marine at the same time?

I'm fairly certain if they were trying to be a Deathwing then they wouldn't be colored green.

Then why is the backpack huge and protecting his head.

I don't know why you're asking me, I didn't draw it. But I definitely did not instantly think of a Terminator so.

I don't think that it can even be argued that a Grey Knight couldn't destroy any other regular Space Marine. But if you excluded the Grey Knights, my money would be on the Exorcists or the Black Templars.