Hrrrrrmmmmmmmmmmm......
1) I can't really give too many details without spoiling his story, but I feel pretty safe in saying that Walker is something completely different. I will say what things Walker and The Brothers have: a) They're all unwilling dimensional travelers; b) ATC's ROB has something to do with it; c) They're all from Texas.
2) For sure, you can use the concept in a fic of your own. But if you're talking about creating some sort of expanded universe thing.... that could be problematic. You'd have to get with ATC to be let in on certain details.
1) I can't really give too many details without spoiling his story, but I feel pretty safe in saying that Walker is something completely different. I will say what things Walker and The Brothers have: a) They're all unwilling dimensional travelers; b) ATC's ROB has something to do with it; c) They're all from Texas.
2) For sure, you can use the concept in a fic of your own. But if you're talking about creating some sort of expanded universe thing.... that could be problematic. You'd have to get with ATC to be let in on certain details.