[@Leolycan] As the Co-GM, I'm going to say no. To playing a warlord of the opposing faction, not to you making a character at all.

The reason for this is that my experiences with people wanting to play the big bad guys are not very pleasant. They tend to turn into control freaks who want to steer the plot in the direction they want it to go, not the way the GM or the players want it to go. Nothing against you personally, I'm not saying that you're the type of person who would do that. But, I don't want to find out the hard way that you are.

That being said, you can still play somebody on the opposing faction if you'd like, just not a warlord.