I don't know, that's why I'm asking. What do you think the most powerful, and in an evil "I will destroy you" kind of way, not a "Oh, I am holy and I can heal the univerrrrrse!" No. Now, some examples, from a video game point of view would be, Combine, Reapers, Covenant, Chimera, and etc. What do you think? Discuss. There's probably a definitive one out there, and I don't know it, but someone might, or maybe there isn't. Right now, I'm thinking about the Engineers from Prometheus 'cause that films been on my mind ever since I've seen it a few weeks back, and the Reapers because of the new ending DLC, that's basically why I made this thread. Oh, and as for the question, I don't really know I'd think the most powerful is, but I'd like to discuss it if you would.
Definitely the reapers, although they're more synthetic than alien.
If we're talking real alien, then the Krogan, unaffected by genophage. Ridiculously tough lizard people that live for hundreds of years and breed at a ridiculous rate. Pretty unstoppable.
I'm excluding someone like Star Trek's Q, because picking a group of inconsistently-written, supposedly omnipotent beings doesn't seem to be in the spirit of this question.
I'm going to go with Babylon 5's Vorlons. Millions of years more advanced than us, almost impossible to communicate with, them going to war basically means they start blowing up every planet with even a tangential relationship with their enemy, and, of course, they've got those funky shower curtain costumes. Babylon 5 is a space station that basically functions as a kind of Space United Nations for all the different aliens, and having the Vorlons open up an office there is as much a surprise as if God had descended down and opened up an embassy in Washington DC.
Warhammer 40k's Tyranids are also pretty damn unbeatable. Imagine the Zerg, but am order of magnitude more powerful, and they've already consumed a few galaxies before moving into our own. Those awful flesh-tearing mouths? They aren't connected to a digestive system! That mouth exists only to tear your face off!
Are we calling Lovecraft's the old ones aliens or are gods separate from aliens? Because I'm pretty sure they'd sort of eat everything.
Gotta agree here (and was glad at least someone put the elder gods up here.) When you figure that the best the other super powered aliens could do to the real bad guy elder gods was put them to sleep.. I gotta go with space alien elder gods.
I'm going with Tyranids on this one. Tyranids wiped entire GALAXIES of life in their never ending desire to evolve and consume. They don't stop, and whenever they are defeated, they just learn, adapt, and evolve.
I feel zerg are significantly weaker then Tyranids fictionwise.