For me, I run with a group of 4 other guys so they can handle all the combat while I do the support.
Lem really shines in places with a lot of allies and blessings/spells with a low monster count. With his super high diplomacy he can recruit any ally. Its not uncommon to do 4-5 explorations in 1 turn.
When you do come across an occasional monster you can either blast them or pop a sanctuary. My friends like battling monsters so its great when i can hand it to them on a silver platter.
at the end of it all, pop a cure and you'll all your blessing and allies back to repeat next turn!
In smaller games its probably better to be a healer/attacker role.