Temple of Darkness

[sector24]

I always put a guy in the province to enter those sites. I'm not sure if it's efficient (you're basically losing research points each turn to recruit units of questionable quality) but having a little army around is helpful when barbarians take a nearby province.

[Agema]

Probably worth it for a D1 mage, especially a summonable one like a revenant - it's not like you'll really be missing those 3 research points.