I do pretty well with summoner for Boss fights and such but for example:

-Fractal Dungeon (Last Boss): What spells do you guys use on these adds that spawn? We require pretty high movement. Do you place DoTs on them? Painflare/Bane doesn't reach the add in the next square. And also sometimes I do Fester and it doesn't say invulnerable but it says "no effect so I do not gain any AT stacks.

-Ravana (EX): The fairies die so quickly so what do you advise here? Do you ever waste AF stacks?

Please, any advise would help. I believe I should help on adds but spamming Ruin II is an MP drain and does very crappy damage just spamming it. And if I do Ruin I, sometimes the mob dies and it's basically a huge DPS loss