One of the downsides to playing a mostly-fire deck, is not getting EM's often. Depending on how fast this deck is, you might not want to add in healing spells, since they might not help you get EM at all. It's worth a try, though, I'd go with heal myself because it heals more, for less cards. However, you need to keep in mind that Holy Light is 1
while heal is 3
, so you'll be losing 1 quantum against using 2 holy lights. I still think that not having to get both of those holy lights is worth paying the extra 1. Maybe have 1 heal and 2 Holy Lights.