I’m going back into my time machine so bear with me. Back in 2008-9, US raid progression wasn’t very well tracked and the T1/T2 boss progression I’m a bit skeptical on due to exploiting, lack of tracking, etc. Only when T2 Chatha was “fixed” and Wing 3 officially released in Feb 2009 did US raid progression go “legit” in my opinion. So in early 2009, yes Ascendant was the top guild on Set, but Bloodlust was the top raid guild on Wiccana, and Reincarnation the top raid guild on Tyranny (pvp server for you EU people!).
I’m trying to find the really old AoC forums where Chatha/Athyr Bast/Leviathus was tracked for US forums (I was one that took over the progression thread back then long ago!) but if I remember correctly Reincarnation got what I consider the “true” US first on Chatha, but can’t remember who was first on Athyr Bast and Leviathus. I just know those 3 guilds were neck and neck and more or less comparable.
When T3 rolled around in Feb 2010, Ascendant was once again the top raid guild on Set, UBL (United By Legend) had become the top raid guild on Wiccana (Bloodlust had imploded due to guild drama), and Usual Suspects was the top Tyranny raid guild. Once again, lack of visibility to the old US raid progression threads, I’m not sure whether Ascendant or UBL finished T3 first, but I think it was close. By that time Usual Suspects had fallen off the pace, I do remember that.
By the time T4 and T3.5 rolled around in 2011, Ascendant had folded and went to Rift. Furious got the first 2 T4 kills, but over the next few years, the US raiding scene was fairly neck and neck between 3 guilds: Immortal Souls (reformed UBL), Epic Guard, and my own guild Rogue Angels.
Eventually both Immortal Souls and Epic Guard folded sometime in 2013 I think, and that’s when RA became the top US raiding guild from late 2013 until today, even though we quit organized raiding in Nov 2018, since there won’t be a T7, that technically leaves us as the eventual winner due to our T6 kills!
So back to the claim of Ascendant being the best guild ever, I don’t think so. They were good, don’t get me wrong, but there were other US guilds just as good in pve during 2008-10, and I’m pretty sure multiple pvp guilds on Tyrrany and Cimmeria were stronger in pvp.