I agree with a lot of this, but, I think the potency should be increased by 50 (so 500) as well as reducing the damage the person to which the fairy is tethered. It's a glorified Rouse at the end of the day, and you lose the ability to use your fairy's and let the fairy heal the party. It needs to be really good for it to be worthwhile.
Also, the increase in Ruin II's potency is a bad idea since 1) that would also affect Summoner, and 2) it's an instant-cast anyway. If anything, Ruin II's potency should go down because you should be casting Ruin I (or III) as a Summoner since it's more MP efficient. I see a lot of bad Summoners spam Ruin II, so increasing the potency will just further encourage this play.
However, I think a better use for Ruin II would be giving it a cast time, reducing its potency, but giving it the ability to reset the timers on DoTs. While I think this is better on Ruin I for Summoner to encourage the spells use (although I have other grievances with Summoner), being able to instantly reset DoTs is super great to have in a fairly DoT-heavy class. It's not as important as, say, Bard, but, Summoner and Scholar tie with Bard and White Mage for having the most DoTs since the shift at 2 each. This does remove the instant cast spell from Scholar and Summoner's list, but I think Drain should have been an instant cast spell anyway.
