User blog comment:Word Bearer333/Best Space Marine Legion?/@comment-3580035-20130324225401

Then the Alpha Legion somehow do something crazy and pull off a surprise win through something like:

- Somehow pull a comet/asteroid off its trajectory and into the planet

- Impersonate enemy commanders all round and generally make a mockery of other legion tactics

- Disappear underground and never be seen until the end of the battle

- Awaken something in the darkness...

- Seismic charge continents

- Infiltrate. Everything.

However, this battle still depends on whether Primarchs are involved, whether its Legion era or current era, whether there is Imperial Navy support, whether Chaos Gods can give blessings/summon daemons as support, etc. If it was current day, it would suck for Thousand Sons to be 99% Rubric marines who have to rely on their sorcerors to direct them skillfuly.