if u are going for Sorc3-Necro3 (before Re:Build)
Sorcerer:
I don’t like Summon Servant. Some do. It helps, at lvl 2, to keep your SP not at 0 for longer once u summon the Demon with the Overwork attribute. The other things are too low value and questionable.
From my experience, max familiar is overall better than maxing Salamion. More damage, more reliable. Better.
Necromancer:
Necromancer has a debuff called ‘Necromancer Bane’. Every time a ‘Flesh’ skill (cannon, hoop, strike) lands on an enemy, it applies this debuff. It increases the damage of your skeletons by 1% per stack. The maximum number of stacks is 50. Excellent in a boss fight.
Flesh Strike gives the 50 stacks all in once at lvl 5. But the damage is not good and costs 100 corpses. U may ignore it. Flesh Cannon and Flesh Hoop are your (only) stacking skills. Hoop is more reliable, but u have to go melee. Flesh Cannon needs aiming and a bit of luck (each hit has a chance of applying the debuff).
If u are not going pvp, u may ignore Dirty Pole. Or just 1 point, for maximum friendly-troll.
I hope this helped. Have fun!