Warhammer 40K v. Mass Effect

This thread was made following the above suggestion from this tread.
Due to the obvious fact that ME would get its *** handed to it by the entirety of the Warhammer 40K, this thread is not about a whole universe v. universe battle.
Rather, this thread is about taking single factions from the Warhammer 40K universe and pitting them against the entirety of the ME universe.
Enjoy

Most of the Warhammer races can do it alone.

True.

Necrons: Move quickly and do alot of damage, though nomadic for the most part.
Eldar: Move quickly, with untouchable Craftworlds, and hit from the shadows.
Tau: Move slower than FTL, but have long-range, hard-hitting weapons and alot of technology.
Orks: WAAAAAAAAAAAGGGGGGGGGGGGGGHHHHHHHHHHHHHHHHHHHHHH!!!!!!!!!!!!!!!!!!!!!
Tyranids: Like the Rachni, but far worse.
Chaos: If the IOM can win, so can they.

Sadly the Mass Effect Universe isn't cut out for universe vs universe right now.

Well, the Necron ftl can send them across the galaxy in an instant, and they JUST DON'T DIE, I would say that the Necrons would slaughter the galaxy easily.

The only Necron weaknesses I can see are the lack of initiative (retconned by Newcrons), and the fact that they can't reproduce.

And when necron_exe fails.

Orks can do it alone as well as all the other factions.