Grifter is apparently some sort of con man (hence the name). And he might have a limited ability to read minds, or read alien minds, or something. And I guess he uses guns, and he’s some sort of vigilante. Seems like he’d fit in well with Red Hood & the Outlaws. Other than that, I don’t know.
Unfortunately, there’s not much for me to write about here. It sets up a good introduction to the character and his world, but it seems that any substantial information (like anything that tells us what the hell’s going on and who this guy is) will be coming in the second or third issue.