It's a wild ride, I've got some screenrecs around here somewhere. The ceremonial dagger would only be in play for Khim as Cerberus gets 7/tick regain under 25% health.

For Cerberus you ride the gates out in fire resist sets, have plenty of remedies as the para is fairly weak; bio, poisonII (when it sticks), and excaliburs for damage.

Khim can actually be, with some luck, soloed down to where it's able to use Fulm. Tail tank to avoid getting petrified. It's definitely the riskier fight as the odds of recovering from even a single Fulmination are worse than a coin flip.

Both of these would be harder on nas than retail due to the extra fifty percent HP all NMs on nasomi get. Also I never quite got tourbillion right, and it's OP on nas as well.