G-Man is an entity with powers of manipulation and deceive beyond anything we could imagine, and he is using these for an unknow purpose.
I believe that the xenians already knew G-Man before the Black Mesa incident, because they knew how to place a foothold against him as shown on Ep. 2
Vortigaunts aren’t representative of all Xenians, particularly because they were slaves.
Let me tell you something. There are no good or evil. It’s all made into decisions with every living thing. There’s only your enemy standing in front of you and you wonna know why? Because he thinks you’re the enemy too.
I mean think about it. Anakin and obiwan argued about it and they thought each other were evil. Sith was evil? Nonsense. But neither was the jedi. They say the Sith are on the dark side of the force which is true but that don’t make them evil and yes, we all do bad things. The Sith weren’t doing it because they were evil. They were doing it because they had to. For peace.
Evil is just one of those words like monster. Something to call someone by.
For every philosopher there is an equal and opposite philosopher; and they’re both wrong.
uuuhh… well dunno what to say after what you 2 said before me but srisly I doubt the Gman is an enemy of any1, he’s just feared by the Xenians like the vorts. They surelly know more about him than what we do.
honestly i don’t think we ever gonna find out. there’s nothing valve can come up with to explain his actions without making him a wuss or an unneeded character.
he plays the role of mistery. and he plays it darn good. we might get some clue about him and his general intentions but in the end it’s up to everybody’s interpretation.
like in horror games. the less you know about the evil the more you are afraid of it. you must never show the evil’s true face.
Um every monster in the game is a Xenian. Just because Vorts were slaves don’t mean they aren’t much of a Xenian. Their world is probably just like ours. We don’t along very well with each other and they don’t get along as well. Like zombies and antlions hate each other. They have their differences. Vorts, Zombies (HeadCrabs), and antlions are all three enemys to each other. I’ve seen all three go at it with each other.
Oh dear god. Xen is a kind of gathering place for all of the creatures that exist there. It seems to be their final stop in escaping an unknown(combine?) force. Valve has confirmed this.
how did we pass from who the G-man is to Xen representative creatures? :S 
I think Gman is a mysterious guy who has a briefcase a very easily loosening tie that hires people and puts them in stasis for twenty years all while never explaining anything about himself and sounding like a creepier Christopher Walken minus the funny.
Mystery solved.
Your sarcasm isn’t appreciated. It would be best if you just insist that G-man is actually Gordon from the future.
^ I agree it would be bettar but he obviusly isn’t. I have already explained the causes befoar
anyone ever read Pendragon? G-Man reminds me of Saint Dane, manipulating everyone so he can take everything over for himself
I also thinked somethin’ liek that the first time I completed the hl1 saga (hl, hl op for, hl blu shift, hl decay)
Now if G-Man was bald…
Then no one would like him 
lol
Also G-Man could really be one of Gordon’s psychological demons.
with magic powers