Is there a specific game this is parodying? I can't think of any iso "tactics" RPGs with "Quest" on the end...
Well, DnD has a feat called Inspiring Leader, and it can give your party about that amount of health, but it's got a ten minute casting time, so it doesn't work in combat.
This is based on a very old snes Shin Megami Tensei spin-off game. I still remember this is like the 4th or 5th chapter of the game. The gameplay is more akin to Fire Emblem than traditional SMT.