Ask a Magician Thread.

If you have an ice wand/staff: Drop slow, then max it in 3rd job with the points you get from dropping comp and thunderspear. You don't need either attack because cold beam will outdamage both, si you might as well get cold beam in 2nd job while slow is still useless, then add to slow when you start fighting mobile bosses at the end of 3rd, when it starts getting useful.

If you don't have an ice wand/staff but want cold beam: If you're planning on dropping both partial resistance and one of the two single-target attacks in 3rd job, drop slow, then max slow at the end of 3rd job. If you want partial resistance, drop mp eater (you won't be able to max mp eater until like level 200 if you go this way).

If you don't have an ice wand/staff and don't care about cold beam: Drop cold beam, but if you happen to get an ice wand/staff later on, drop both 3rd job single-target attacks and use 3rd job points to max cold beam.

Edit: Cold beam has the same range, but comp can't go through walls.

I was going to get a Lightning Wand...are both Comp and TS useless?