"Thassarian is the first death knight to join the Alliance […] One of the few death knights of Acherus who maintained a genuine sense of honor and brotherhood, […]
[…] Thassarian then traveled to Stormwind serve King Varian and became the first death knight to rejoin the Alliance. […] Thassarian remained a loyal soldier to his king […]"
either it’s a line in that death knight manga or it’s bc he’s the first known to have joined the alliance
either way i imagine the point is he was (one of) the first.
he VERY clearly dissavows + takes a big on the Alliance and any loyalty/duty he has toward it in WOTLK.
" Thassarian says: I cannot return home with you just yet, Leryssa. I am not quite done with the Scourge.
Leryssa says: Don’t leave me again! You want to fight for your country, but they don’t even want you! They sent you here to die!
Thassarian says: You might be right, sister. My obligations to my land and King have been fulfilled. But there is still something that I owe to myself."
(point being, he’s hardly a stalwart alliance lover)
1 expansion later he joined the Alliance to retake Andorhal wasn’t he also in charge of the entire attack on the area too?
Clearly in WotLK Thassarian did obey the vow he swore at Light’s Hope Chapel to defeat the Lich King which is why he ‘owe something to himself’’.
So talking poop at the Alliance in WotLK do not really make much difference since he is serving the Alliance in Cataclysm.
With Legion we see literally every Horde/Alliance go neutral, we have so many order halls that goes that path so as it is stand right now we do not know how active Thassarian is within the Alliance so you can’t really say yes he is active or no he isn’t.