Alpha Legion are the most powerful Legion?
Some portion of them are engaging with Istvaan Remnant. Another portion of them rebelled(led by Omegon). They are suffering virtual inter-Legion civil war.
Still, they take both Scars and Wolves and winning. Chondax was just a beginning and they are fighting with Vth and VIth across galaxy entire, even as far as the region of Pale Stars. Remember by nature, both Scars and Alphas are widely dispersed Legions. Moreover, in Alaxxes, a fifth of Alpha Legion main force(led by Alpharius) are greater and mightier than Wolves entire fleet.
It is stated they might have comparable number to Ultramarines and are able to field previously unthinkable number of Legionaries simultaneously across the entire galaxy. It seems even conjectured upper limit of 180,000 strength is severe underestimation. I think it is quite plausible that Alphas are the most numerous Legion.
They never fail except sheer turn of chance or fate. They have practically no weaknesses. They control and exploit each and every factor and element and if enemies somehow achieved meaningful victory or breakthrough, it is just because they allowed enemy to win, with possible one or two exceptions.
Novels and Forge World Books already pretty much established them as one of the most powerful and fearsome Legion. And it seems if anything, they are increasingly nearing territory of unadulterated Mary Sue, if they did not cross the line long time ago.
Last edited by Santor; 10-31-15 at 10:56 AM.