User blog comment:Unmei Suiheisen/Abyssal Vortex help/@comment-27830017-20170408174655

So, the basics of Abyssal Vortexes are that they require Arcana affiliated with the continent that they're located in. In Cuniali's case, she's in the Holy Capital area, which means that every unit that does not originate from the Holy Capital Tavern, area, or otherwise will face a debuff that makes their stats weak.

In Baglis' case, he's in the Nine territories continent so you have to beat the floors with 9T arcana. It's possible to use other arcana in your team that isn't 9T if you really need their abilities, just that they wont do much damage.

In addition, friends can be from whatever continent and will not face debuffs from the vortex, so you can use them liberally especially if you're missing a core unit from that specified affiliation.

For Cuniali, scramble together the best Holy Capital team you can manage and go with a good friend (Kain V3 is basically your cheese machine for most of the floors).