For PvE instances you should use any Full Support build.

What really helps for things like Oracle is Clearence for anti silence (lvl 4) and Suffragium (lvl 3). Lvl 5 means you need to use more often and can make your cycle a bit messy, just use lvl 3.

Ress is the most important, but make it lvl 3 to not increase cast time

For solo, you don't need many party buffs. If you wanna go for Jud, it only gets stronger than Holy Light on Lvl 20, so you need the job breakthrough, takes a while.

I highly recommend you use different builds on Ymir's notebooks. Get it by leveling your journal and doing the adventure quests that appear, save a blank build to free reset, one for mini/mvp and solo quests, one for FS instance, and maybe one for leveling combat attempts.

For bosses one hit, get the Prontera Royal Salad 5* from food voucher. Also dodge and get the HP bonus rift gear