I HATED the new Renbu system from DW6 so I do not recommend it as a starting point. The renbu system works like a frentic kill-fest incentive. The more you kill enemies, the more the renbu bar fills up. It goes up to 4 level, 1-3 and infinity ( I think or it could be 5!). Each level correspond to the number of additional attack a character can chain in a button mashing combo.
The only problem here is that the renbu bar drains naturally whenever you're not killing and running around from objective A-B could nerf your character in the most fustrating way as you arrive on site B with only 2 renbu bar.
Get empire, it has significant improvement through the inclusion of some Turn-base Strategy as well as an improve renbu system where the attacks are now linked to the weapon itself and you don't have to worry about the renbu bar steadily dropping when not in combat.
