I don't know if the title maxes sense but I want to make so that I can appy shields to units without giving them max shields. Maybe some trigger or data thing that causes the max shield amount to match the amount of shields the unit currently has? But I don't know how to do that either.
I'm not sure if this is what you want... but the Auir Immortal has an ability where it can gain a barrier that absorbes 100 damage. It's like a shield but isn't one, so it doesn't affect existing shields.