So right now I’m closing in on finishing Diev c3.
Can’t say I’m particularly thrilled with going Druid1>Druid2 or Druid1>PD1. Originally I was going to go Oracle1>Kabbal1 but now I’m starting to reconsider that to Druid1>Kabal1. I was curious to know what people thought of Oracle1>Kabal1. I don’t care about Battle League, more so wanting to be effective for PVE/WB/GvG.
With that said I’d love to see what some of you think 
As much as I would love to help, my knowledge in the oracle class is rather limited. Hence it is better not to theorize and led others to the wrong path due to bad advice.
Anyway, I was in the same dilemma as you previously, having a good cleric2->diev3 core and choosing my 6th and 7th classes. Druid2 was the initial choice, but was not thrilled about it due to it leaning too much into dps rather than providing passive support for the party. I wanted Kabbalist as the 7th class instead of plague doc.
Hence I’m left with other classes to choose, which oracle and paladin c1 stand out as the 6th class. Chose paladin1 in the end though, but I can tell you what leads me to the decision when choosing between oracle and paladin.
Oracle is a pure support class, with numerous good abilities like Arcane Energy, Counterspell and Prophecy.
Arcane Energy at lvl5 gives around 15% extra SP, at around lvl200 (on avg a player’s SP is around 2k+ at that level). Hence with the arcane energy buff it gives around 300-450 additional SP limit, which translates to players being above to cast an additional 5-7 spells. This is a really great buff for a support. But having a bigger pool doesn’t mean regeneration is faster although it combos pretty well with Kabbalist’s Ein Sof.
Counterspell removes all ground effects around the oracle for a fixed amount of time. Currently until now I don’t feel the need of it much in pve, dungeon parties are surviving well with just moving out of the affected zone rather than continuing the fight within the debuff/damage area. GvG it can be extremely potent though.
Have not seen prophecy at work, hence not too sure about its abiliites.
The above are the points which I took into consideration when I was choosing in-between classes. Hope it helps.
I’m actually on the same path as you.
Cleric 2 (for lv 10 Heal)
Diev C3
xxxxx Rank 6
Plague Doctor (Healing Factor FTW)
After a lot of brain storming, I choose Cleric C1 (for the Resurrection) because my target is to complete the Earth Tower, do you know that you can not use Soul Crystal to self-resurrection in Earth Tower? If you die and there’s no Priest to resurrect you, than you have to respawn from the 1st floor.
Unfortunately Priest C1 only gives benefit on Ressurection.
With Druid C1, we have more DPS.
With Krivis, we have Daino and easy debuff to prolong the Incineration.
But , since I planing to stop playing in this iTOS and move to my local (Indonesian TOS), I will try Oracle as my 6th rank, 10 job level to go.
Let me inform you on my experiment with Oracle after I reach 6th rank.