(Grr, my computer has a mind of its own and tried to post this comment before it was finished, so I had to redo it. Sorry if you got two versions.)
Ah! Maybe "Lord Beastmaster", as that's the usual translation (I think) or "The Lord Who Reigns Over the Beasts"
I suspected as much after you mentioned that you thought it was Xellos' meeting with the Beastmaster. The kanji should mean wild, so it fits, but any idea how it's traditionally pronounced in this word?
I think the missing kanji is a rare form of "kiba", or "fang".
Ah, so it is. I was getting very tired by that time, so I had no idea how to identify the strokes and find it in my beloved SKIP dictionary (turns out it is there, under the "solid" character heading). It's in Nelson too. Amazing how easy it is to find a kanji when you KNOW what it is...
Nice job identifying motte -- looking at it now, I can see that's what it is, but I doubt I would have ever figured it out on my own even if I got that far.
Your translation of the next bit looks mostly right to me, but I really struggle with the manga-problem of sentence fragments. What do you figure the (possibly unspoken) verb governing ataenkoto o is?
"[Unspoken verb: possibly "I request!"?] the ability to cause(ataenkoto o = ataeru koto o) death and retribution with the power that you and I possess, when our road is blocked."
I have trouble making ataenkoto o the direct object of chikara (o) motte, "we have the power to cause" -- does Japanese even work like that?
Plus, my complex Japanese grammar sucks. In "ware to nanji ga chikara motte," motte ought to agree with the subject of the unspoken verb (e.g. "I ask having" = I ask to be given), chikara is the object of motte, and ware to nanji ga is the subject of motte -- right? Thus, "having the power that you and I possess" or "by means of the power that you and I possess."
Ugh, my Latin is showing. I always have to know what agrees with what, and I suspect manga authors often don't care. ^-^