Demon Slayer questions

Just so were clear on force shields:

shields come pre-potentialed and level up
Force shields cannot be scrolled
Force shields increases maximum dark force
And by description i think you need a force shield for:

Force Guard
Description: Add a chance to block enemy attacks using a Force Shield. Upon successfully guarding, you will recover a small amount of HP and Force.

1 Chance to Guard: 2%, Recovers 1% HP and 1 Force
15 Chance to Guard: 30%, Recovers 3% HP and 5 Force


so whether you pic attack shield(more damage) or Force Shield(30% chance to guard, recovert as well as force charge) is up to you