The more partial information we get, the more I think that OoB just works as a normal channeled spell. A total speculation, but I think if you got Sure Spell with Spiritual Chain. attacks should not interrupt your OoB.
@jonnyboyxu13 - most people will tell you Krivis, but I think priest will be faster. C1 Krivis is surely faster than C1 Priest. You will however spend much more time on rank 3.
At C2 Krivis gets splash on Zaibas, while Priest gets Sacrament. In theory this favors Krivis, but unless you level with Peltasta it is hard to get decent mobs. Zaibas has a relatively short cooldown but it is still there. Priest deals great auto-attack damage, with zero downtime, even in full INT build.
As soon as you hit high 3x you can go farming erognomes (or however they are called, the big furnace things in Chapel F2). The place is so crowded, that you hit only 2-3 with Zaibas anyway. You kill them way faster with priest. You get to level 50 very fast. From there you do 3-4 runs of Tenent dungeon and you are suddenly 5 job levels from Sadhu. From there, on the maps I have seen so far, the mobs are so sparse that you canât mob decently for Zaibas.
In theory Krivis levels faster, due to AoE. With current spawns and current population however this doesnât work that well, and 0 downtime of priest just wins.