i think the banes and other seasonals should be attacking planets ! if they attack one of your planets and you fight them off, perhaps you get a special planet structure on that planet ?
if they attack an unoccupied planet , maybe they colonize it , and when you take it from them you get double green badges and a special structure on that planet ?
if they are attacking an enemy planet and you defeat them and conquer that planet , perhaps triple green badges and a very special artifact reward

sound cool ?

I can agree with the concept but not with the specifics of this suggestion. The idea of the seasonal enemies taking an active role against the the player(as in blockades) would be really cool, and as with other blockades would give some sort of artifact. However my problem is with the idea of getting more green badges based upon where they are attacking. As of right now green badges are one of the hardest badges to get so having one planet having the opportunity to give you three would be a bit much. So how I would change this is that I would keep the green badge at one badge per invade, no matter the location, but keep all of the cool stuff: the npc controlled planet and the ability for them to attack your planet. Maybe if they have conquered a planet, rather than getting an artifact, they leave an artifact on the surface of the planet that you would have to extract if you wanted to move it to another planet. Just my two cents

sounds cool , i was just trying to get my idea out there and ppl talking about it . i like your suggestions