Wall of Force.
At the current you have a general utility spell, an offensive spell, a buff spell and hence the one spell missing from the suite is a defensive spell.
And what a defensive spell. Wall of Force gives you invinicible protection against all manner of goons, with only Passwall and Disintegrate being able to destroy it (oh all right, and Mordenkainen's Disjunction, but this isn't an issue for the time being): meaning that, since Passwall is rarely memorised and hardly ever encountered in monsters, foes of equivalent power pose no threat.
Furthermore, Wall of Force enables you to make full use of Ghostform. Some DMs disallow it as abusive, but a hemispherical Wall of Force on the ground can allow you to move out of the Wall, through the ground and pop up and cast spells. If wounded, you can withdraw back: if hasted, you can move out and back all in your action.
Finally, as a utility spell it is not to be underestimated. If you're being chased by foes above your level, instead of spiking the door or using Arcane Lock, slap a Wall of Force in the way. Instant defense. In buildings, you can use it to segregate opponents, breaking a strong encounter into two weak ones.
It is, without doubt, the one to go for.
Failing that, consider Feeblemind or Dominate. I don't know if you many spells which attack Will saves, but these both strong in this department: if you tackle arcane spell users, take them former; otherwise, the latter is more useful.
At the current you have a general utility spell, an offensive spell, a buff spell and hence the one spell missing from the suite is a defensive spell.
And what a defensive spell. Wall of Force gives you invinicible protection against all manner of goons, with only Passwall and Disintegrate being able to destroy it (oh all right, and Mordenkainen's Disjunction, but this isn't an issue for the time being): meaning that, since Passwall is rarely memorised and hardly ever encountered in monsters, foes of equivalent power pose no threat.
Furthermore, Wall of Force enables you to make full use of Ghostform. Some DMs disallow it as abusive, but a hemispherical Wall of Force on the ground can allow you to move out of the Wall, through the ground and pop up and cast spells. If wounded, you can withdraw back: if hasted, you can move out and back all in your action.
Finally, as a utility spell it is not to be underestimated. If you're being chased by foes above your level, instead of spiking the door or using Arcane Lock, slap a Wall of Force in the way. Instant defense. In buildings, you can use it to segregate opponents, breaking a strong encounter into two weak ones.
It is, without doubt, the one to go for.
Failing that, consider Feeblemind or Dominate. I don't know if you many spells which attack Will saves, but these both strong in this department: if you tackle arcane spell users, take them former; otherwise, the latter is more useful.
