The two images below were taken immediately after a single match, while playing as Sedna. Prior to this match, my achievments had been wiped clean (for Sedna, at least) as per the current favour/acheivement bug, so (I assume) I was working from a clean slate when this happened. Take note of the "Sedna the Exterminator" achievement in the first image. Kill 25 Demigods in a single match. Simple enough... When dealing with bots, at least. [e digicons]:blush:[/e]

The following image was taken at the same time. Note the fact that the requirements for "Sedna the Butcher" haven't been reached.

So. I've killed 25 Demigods in a single match, but still haven't managed to... Uhh... Kill 25 Demigods. Wait, what?
Unfortunately I didn't bother to check my killcount at the conclusion of the previous match, but It's my guess that the killcounter for Exterminator is tallying solo kills & assisted kills, while Butcher is working solely on solo (non-assisted) kills. Not a huge issue, but I thought I'd better make note of this, just in case this ISN'T the way that the devs intended these achievements to function.