I personally disagree with changing Selene into a fairy that increases damage in any way because it would enable the same griefing as back when WHM lilies were a damage loss, it would enable SCH players to do absolutely no healing and claim damage loss when you ask them to pull their weight. We already have this problem now with the people who exclusively use Aetherflow on Energy Drain no matter what, but at least the fairy is always healing, give the option of a damage fairy though and you'll get SCHs that will grief the party by outputting a grand total of 0 healing (depending on whether a damage type fairy retains Embrace or has an autoattack instead) and will cite damage loss when you ask them to do some healing.
It would be like solo healing without the benefits of having a 5th DPS job.