Chanter could main heal but at first was definitely secondary, thats another story though. It had static buffs that could be turned on that boosted different stats. Depending on how it was spec'd it could have 3 or 4 static buffs up at once. It could boost attack, matk, pdef, mdef, run speed, and patk speed, matk speed. It was a beast in PvP solo or in group. So, I'm imagining the astrologian as something similar. Uses cards to boost stats. I think at most it will be able to hold 2 buffs up. If it has to keep popping them like how most cd's are in FF with stupid short up times I will definitely hate it. It needs long up times or actually solo healing will be ridiculous for light party's.