So overall legion equipment can be used at the beginning, but they lose their effectiveness after a few chapters due to lack of speed and range, Dynasty is good but has poor damage affinity, heralds are good at late game. Dynasty also has poor shadow abilities, with a few exceptions, as they take so long to complete that our shadow energy gets depleted. I don't like legion because it's shadow abilities are not good, and miss their mark most of the times. I personally used legion's nightbanes with chop till they drop ability or any such axe till chapter 6, then switched to chelicerae, blood reaper etc. The weapons such as kusarigamas, glaive, whip katars (chelicerae,etc), etc are the best, especially for dealing with strong opponents such as shadow mind and shadow. Heralds are the best faction at late game, especially after chapter 6. Dynasty is only has some good equipment like composite glaive, nunchucks, sabers, dadao, etc, in which dadao and composite glaive is best. I am currently in transformation- June's plane and according to me legion is the best faction for first 5 chapters upto chapter 6 where opponents start using faster weapons.