Never thought about divine veil but you're right.....having a healing req is very gimmicky....no actual perk. You can always time it properly by either inticipating the inc heal or heal yourself. But it's still gimmicky...
How about instead they make divine veil have some personal utility but also if you're healed while it's active the party get the shield so it would be liken to the way dark art modifies drk abilities (base effect +heal= additional effect).
Or just remove the healing requirement
