What should I sub my Arcanist as?

[Doktor_Q]

Arcanist/Runemaster can get bonus TP and free energy, which never hurt a caster. You can sub into medic for additional healing, or into Nightseeker for, at the very least, Shadow Cloak and Not Getting Killed. Fort sub automatically grants durability to a character, if nothing else, and... well, you already have Medic, but there's nothing wrong with more copies of Auto Revive.

[Wolkenritter]

[Dangerus]

Nightseeker/Bushi FTW!

Anyway, the two Arcanists I have are subbed as Medic and Runemaster. Arcanist/Medics do pretty good healing. Arcanist/Runemasters though are better Runemasters in my honest opinion.

[emailboxu]

[Wolkenritter]

[Wolkenritter]

[Snowdome]

[scy]

On the subject of Arcanist/Runemaster, it exists to streamline the buff/debuff to one character so an actual Main class Runemaster can focus on actually dealing damage. The difference in the debuff Runes isn't large enough to matter for the turn efficiency. /Medic is good for the extra general utility though. These are the two most common subs though and for fairly good reason

Regarding Spotter being "enough", it depends. If it's similar enough to Nine Smashes from EO3, it's probably around a -55 penalty to Accuracy. Spotter would be +40 and the base HIT formula can grant up to +30 so both of those could compensate.

[KitsuKitsu]

The standard is usually Arcanist/Medic. It's pretty strong; great as support.