How can you tell what convenants do? And what does the one do that you can find right after the tutorial area? I said no cause I remember there being one that made the game harder.
As far as I can tell it's not explained anywhere in the game. You just need to notice things. I wont know if more enemies respawn because I'm going in with the Company of Champions right off the bat. I know for sure that I deal less damage to enemies. I'm pretty sure they can hit me harder. I don't know if they have more HP.
Another update. I just engaged in my first invasion and I won. I directed the dude to the forest bonfire and let him clear out the enemies. We then had a very nice match that lasted a few minutes and ended with GG messages. I didn't seem get any souls from the invasion (maybe he left souls on the ground?), but I did get a nice red stone as proof of my victory. It's used to open yourself up to invasions it seems.
I thought that invaders could use healing items when they invade? My estus flask and life gems were grayed out. Maybe the Company of Champions doesn't let you use healing items? Can someone who's invaded confirm or deny this?