Doomcaster Suprax

[Riversong-earthen-ring]

Anybody know for sure how to get this Argus rare to appear?
I know he needed 3 people originally and was then changed to a solo summon. After that it seems to get abit sketchy and I cant find out what you need to do now to summon him.

The weird thing is I summoned him one time with 2 people the other day (me and a trial character I made on my other account) but since then I cant get him to appear!

Glad that he decided to show up once so I could get the achievement but Id kinda like to farm for the toy too.
Any ideas why he showed up once but not since??

[Papudeath-outland (Papudeath)]

Looking around a little, I can see that other people have had similar problems. For some it spawns when you activate all 3 runes by running over them with a mount by yourself, for some it activates when they touch one rune. Probably worth trying both. If it doesn’t work, well, it’s probably a pretty bugged encounter, so not much you can do apart from reporting it or asking a GM for clarification.