DFFOO [JP][Alphinaud Lufenia+][Alt Run] Maximum Toxicity: All the HP poison characters in the game
The 3 HP poison characters: Yda, Alphinaud and Exdeath. Sometimes the quantity of poison matters over the quality of a single one.
Not more efficient than explosive direct dmg, but fun to mess around with. I am quite surprised that the Lv.80s still do decent dmg with Alphinaud as sole support. This is more about quantity over quality though, so it is not about pouring the highest amount of ATK possible, but drowning the enemy with a large amount of poison sources with serviceable ATK.
Field turn HP poison:
In terms of field turn poison, there are Exdeath's BT effect and Alphinaud's LD effect. Even though Exdeath has only 3 turns of effect, Yda's break - 2 free turn loop can lock down the enemy for quite some time, even possible for more than the last 50% of the bosses' HP as you can see.
Enemy turn HP poison:
On top of the Alphinaud and Exdeath BT poison, there is Exdeath S2 and LD debuff and Yda's Touch of death framed poison. So when they do eventually get a turn, especially during the 3 teleport turns after the 49% threshold, they would take 5 HP poison dmg each time.
When all things are in place all the poison should stack up to around 240K per enemy turn and 120K per field turn. So the party needs much less direct dmg in comparison.
Note about Yda loop:
Yda's S2 sometimes have high enough turn rate to become an "instant turn" rate move, so other than her C65/Calls it can be used as a buffer gap to wait for the break recovery.
Otherwise choose between S1 and EX/LD on the 1st consecutive turn depending on whether the other boss has recovered from breaks.
Poison potency:
Most of the ATK buff comes from Alphinaud and the CAs. Alphinaud has a harder time to get the maximum amount if he gets targetted and debuffed, pushing the Sazh ATK buff away. Therefore Cait Sith's CA is used to give him the framed cheerful gift buff for more base ATK besides the LDCA effect for the latter half of the battle when Exdeath simply does not move and holding it. The LDCA of both Sazh and Cait Sith also act as a semi-counter for the 999% BRV dmg reduction during the Adamant Skin mode of the boss at 19%.
I think overall Exdeath's direct dmg under this setup is the thing that is particularly lacking if he does not receive battery beforehand. There is not enough ATK and BRV gain for him to be more proactive. Whenever he gets his BT+ he should get inherit BRV gain to fix his problems. Not that I would mind but it seems that his BT poison's ATK scaling is still decent.
The worst thing about this comp is actually waiting for all the poison to go off lmao. It really takes ages.