Fights take place in ST Federation space.
Unless these are all somehow horrendous stomps in favor of B5, the Q stay out of it (maybe because they're the ones who brought in the B5 aliens).
How does each force in the Star Trek Universe (Federation, Klingons, Romulans, Cardassians, Ferengi, Borg, every race EXCEPT the Q) fare against an all-out invasion by
1. The Vorlons
2. The Shadows
3. Lorien
4. The Thirdspace Aliens
Bonus: universe vs universe all at once (minus Q)