It... really isn't that bad. (As far as Ultimates go)
It definitely follows in the footsteps of stuff like FFXIV in that DeNA balances with the assumption that most equipment is going to be non-synergy (current mythril-dump controversy aside)
It's basically:
- RNG applying Poison and Slow to Belias
- RNG not having the adds cast too much shit like Gigaflares before they go down, which should take two turns, tops.
- Slight RNG with Belias in the Weak face not facerolling your team. With Slow up this isn't too bad.
The adds have less than 40k HP. They're basically about as tanky as the Shadow Creepers in Bahamut SIN.
edit: I think I'd better rephrase:
This FFT event's tuning is such that it doesn't expect you to be sneezing RS gear out the wazoo like, say, a FFVII or FFX event. Yes, the Ultimate *is* an Ultimate level and isn't a pushover, but if you're struggling, it's probably not from a lack of RS.
It was the same for the FFXIV event. If you pulled something like Thancred's dagger, you probably wrecked the +++, but it was just fine without.