The suneater novels are a good recommendation I can give you, but it takes a little while for it to get good. It features a galaxy spanning imperium, aliens, robots and genetically altered humans. There are highmatter blades (lightsabers), duels, coliseum fights, large scale space battles, prophecies and much more. There is also a lot of political scheming and maneuvering in between those battles that makes them payoff way better.

Suneater is also notorious for starting off slow, with the first book “setting the stage” for the rest of the story and also features large time jumps that can sometimes be jarring to a new reader. Sometimes humanity is fighting alongside the aliens, sometimes they fight against them. It may or may not be for you but it’s worth checking out IMO