@SnonJow
I already did most of what you suggested. The idea is that Gollum has a certain chance to spawn on each map (not done yet) and once the player kills him, he receives the ring and is able to transfer it to other territories (already working, altough with some workarounds). When the ringhero is recruited, he will stay as a normal unit with the army leader (already done). Once gollum is killed, he does not spawn again.
Things that are not possible:
-make the ringhero recruitable on the living map, once a certain condition is met. Heroes and units are either recruitable all of the time, or not at all :/
-Make the ringhero an army leader. Army leaders can only be recruited on the living map. Heroes you recruit during a battle can not become one.
-keeping the ring, when the unit carrying it or the ringhero is killed during a simulated battle
- SnonJow, MattTheLegoman and The_Nazgul like this