DFFOO [JP][Beatrix IW] Seymour is here to fix the problem that he caused by shattering those shields
56No Beatrix FR and the only Beatrix FR friend disappeared as I was approaching the Shinryu stage. So in this case, I went to the other side of the spectrum. Instead of off-turn dmg relying on enemy turns, it is time for full on direct dmg with no enemy turns.
This boss is not all that hard and it is squishy. Though I can see it causing frustration and trouble with the simultaneous BRV+HP shield mechanic. It is also for this reason that potentially it can eat up your precious FR turns doing no dmg to them, so best not underestimate it.
Boss info:
Force Mechanics:
0%: 100% BRV dmg reduction on elemental BRV other than thunder
FA: Shockwave+ (break recovery, Guaranteed hit, AOE BRV+HP)
It also buffs BRV dmg up/DEF up/Action Delay Down/BRV back regen/BRV regen
FT: 6 turn
HP dmg up on all bosses
Weakness:
FA that dispels and deals lightning magic BRV dmg
If you need to and don't have Beatrix, you can lightning enchant Seymour FR.
Threshold mechanics: (main gimmick for this fight)
20/40/80%:
Boss would be on fire. While it is on fire it will gain the following effects:
(1) 4m BRV and 4m HP shield at the same time
(2) 50% BRV/HP dmg taken reduction
If either shield is dispelled, the above effects would be nullified.
10/30/70%: (10% HP from when "on fire" has started)
Depending on whether "on fire" has been cancelled, it will trigger a different break recovery attack:
(1) if yes, Leave dance (AOE BRV+HP) and buffs itself with ATK up
(2) if no, fire leave dance (reduce to player 10% HP attack)
Fire leave dance also reduces your buff duration by 6 turns (most likely wiping them) and buffs themselves with "Evasion Up".
Should you break multiple shields and thresholds in a state that they cannot attack (summon/BT), they would accumulate all of these attacks and fire all of them in one go.
Other than these, the boss mostly just do a ST BRV+HP attack that helps itself recover from breaks, buff themselves with SPD up; or do a mustard bomb (BRV only) to decrease your DEF/fire res/ATK. They are usually not a problem, but if you do trigger that fire leave dance and have fire res or get broken, it can hurt really bad.
Approach:
The main gimmick in this fight is the BRV+HP shield.
Since both a 4m BRV and 4m HP shield spawn at the same time, due to modern day attacks mostly rely on dmg refund or BRV dmg to deal actual HP dmg, it is very easy to get stuck in a loop of doing absolutely no dmg to destroy even just one of the shield. This can also ruin a FR phase with turns wasted doing nothing.
If you are using Jack (which I did in initial clear), what you can do is preemptively plant -BRV before the shield spawns, so his last hit can still get that HP dmg. Though one difficulty for Jack here is soul cage has A LOT of break recovery moves. If you don't have an idea when the boss was last broken, that -BRV can go byebye really fast and restoring it would prove difficult with the shield in the way. So using Jack here is kind of a practice for your break management and timing.
In terms of this run, the idea is break the HP shield with launches and AOE. Raines/Pandemonium here provides extra HP dmg (also cap in Raines's case) during launches to dispatch of the shield efficiently.
Meanwhile Seymour with all the HP dmg cap up from Aranea FR, Raines and his own BT would destroy the shield with his AOE follow-ups. To avoid getting stuck in that limbo of 0 BRV/0 HP dmg, it is best to hit the one that does not have the shield on and let his total annihilation take care of the other one's shield. I sacrificed a bit of follow-up triggers with Requiem for this and boosting Aranea FR % with a break.
The last 2 thresholds are very close to each other. Bomb it with strong AOE when the FR % is strong. Getting a perfect skill selection sequence is not worth when you get stuck in the 0 BRV/dmg limbo.
I would also advice against using Prishe's BRV hit+1 to smash the BRV shield instead of the HP shield. I tried and it would seem that smashing a 4m BRV shield is not exactly the most efficient way to do this lol.
I also thought about using Enna Kros and bomb them with intense firepower and skip everything. It is a shame that you would need other dmg insurance for her, since this stage resist elemental BRV dmg (which has been a trend for elemental FRs).