Regen only applies when unit is knocked out.
Fair point that I could've added regen during the battle encounters as well.
I think that Regen, as it is, is perfectly fine. However, I'd recommend adding a tooltip to explain how a unit's stats function, and how Absorb functions. At first, I had thought that Absorb would apply all of the stat modifications, but it only seems to do a percent of the total (presumably tied to the Absorb Rate upgrade?)