by Samthere
There is no reason to believe that healing ray applies to everyone. Healing ray allows you to use your heart dice to heal other monsters, not all monsters. So, instead of using your heart to heal yourself, you can give it up to heal a different monster by 1 point.The card says that they must pay you 2E for each damage that you heal. If they are at max health, you didn't heal a damage, the same way that you don't heal damage if you roll hearts for yourself at max health.
Whether you can use heal ray as the king is less clear, but in my games I would allow it - the rulebook says you can't use heart dice, but the card says you can. Since this is a rules conflict, I go with the golden rule of "specific beats general", and thus the rule written on the card overrides (unless the rulebook specifically overrides the cards). Since this is Richard Garfield, I'd say it's fairly safe to, in general, obey this principal.