So I have been playing with that character lately and I thought that, being a special job, it is really underpowered. Hence, I have a few suggestion balancing him and making a good mage ( Hopefully better then david oscuro and el Mago.
Here are the modifications:
First skill: Good idea to have 2 water elementals. But their damage sucks in the end (Specially considering that you have ten rebrith points and when to get to Aquiles or even try to get your gema rebuild. Plus he is suppose to be THE summoner. But job2 cabalerro de la muerte skill just onw him on the summoning part. Hence I would say, make turn this ksill into summoning two fire elementals (for tank I would suggest around 10k-15k hp each and 2x or 2.5x int physica dmgl each not and same armor as bear). Cooldown 25-30 secs. that way your elementals do get kill but after few secs you can recast.
Second skill: Either rework the illusion making it able to deal some dmg, or make up a second summon skill. I have in mind a neither dragon summon (7.5k Hp 3*int dmg less armor then fire elemenals around 2k-2.5k) Cooldown 20 sec.
Third skill: Above all skill I think that's the one that really needs rebuilding. Either upgrade its dmg to like 5*int or *6int or creat an aura (buff would only apply too summoned creatures and/or summoner) like command aura or defiance aura.
Fourth skill: Should be modified because of all previous change. Still in the summoner's theme, I would say that a cloning skill would be really sweet. You could only clone one of your summoned unit but the cloned unit would deal more dmg (like 1.5* summoned unit dmg) have double hp same armor but take more dmg then natural summoned nit. Cooldown 40 secs.
I think with those skills it makes this class way more interesting, (you have to distribute your stats less in strength and agility) not too overpowered since eventually Arma dmg may serve you more then those summon.
Please feel free to comment. ^^