My favorite Idea for the mark cards so far, loves how it expands on SoFr's mecanic. As to balancing, looks pretty good for me. Quint is usable on any creature and costs 3
. This works on about half of the cards, and has to be renewed. Only problem I find with it is that it powers itself, generates 1 quanta per turn, ability costs one per turn. Its kind of like seraph's ability, but doesn't require an off element. However, 2
may be a bit too much.