Yeah no way Tyranids OR Necrons can stand up to Chaos Space Marines AND Demons, if they ever did make it into the Warp (Somehow?) then they would be SOOOO mind Fu*$3d that they would rage quit .
Uhm..... Daemons vs. Tyranids would be interesting.... Especially if they should end up fighting for hundreds of years as the Tyranids would have perfected their genes and what not against them PS: The Tyranid Hive also has extreme strong warp powers, almost no Psyker survives direct mental contact with them, so I am sure it could also kill plenty of Chaos Marines, especially Sorcerers so perhaps the Hive Mind could evolve to a point to actually mess with the Warp to get rid of the Daemons...
New Eldar game plan! We all kill ourselves then when we do that we can retake the Galaxy! *Slits own throat*
Not really. Chaos is born out of the emotions of mortals. Get rid of mortals by nomming them? BAM Chaos is dead.
Lol no way can the Necrons or Tyranids get rid of ALL mortals since they would eventually unite against the common threat and wipe the galaxy with their faces. BAM Chaos Wins .
Unite against the common threat? Like they've been doing for the last - not ever? Yeah no. I really wish 'nids didn't exist. They're such a dull faction who do nothing but detract from the setting.
The Nids exist as a catalyst for the end of days and the 'final' fight of the Imperium to save itself or be damned forever. They may have no personality, but as a threat they are damn terrifying (from an in universe perspective of course.)