(Love it or Hate it I've played FFBE since day 1, yes it has plenty of flaws, and in it's current state I'm not spending on it but I still love the Story)

(also excuse the poor Photo Shopping, I've only used it a hand full of times lol but it gives the visualization. I did this pre Sephiroth face fix and I'm too lazy to go back and update it)

Cloud:

Rain's Outfit:

- Boost PATK

- Blazing Soul (Fire Ability damage +35%)

Crimson Saber:

Extreme Nova: 400% Phys Fire Damage [single enemy] Also lowers Fire resistance [Single enemy] [min] 12 seconds

R. Abilities:

- Boost ATK

- Boost Fire pot.

Spt. Materia:

- ATK Boost II (Ability Damage 20%)

- PATK Boost I (Phys Ability Damage 20%)

- X Sigil Boost (+2)

Sephiroth

Lasswell's Outfit:

- Boost PATK

- Tranquil Spirit (Ice Ability Damage +35%)

Purple Lightning:

Absolute Mirror of Equity: 400% Phys Ice Damage [single enemy] also lowers Ice resistance [min] 12 seconds

R. Abilities:

- Boost ATK

- Boost Ice pot

Spt Materia:

- ATK Boost II (Ability Damage +20%)

- PATK Boost (Phys Ability Damage +20%)

- O Sigil Boost (+2)

(I started floating this idea before Sephiroth was even release so my first idea was Zack for Lasswell's gear but even though they have similar hair I figured weapon type would be more important to match lol)

FFBE:

-NV Young Sephiroth (First SOLDIER Sephiroth) (Brave shifts into his Ice garb, built in focus, maybe a Meteor type MP scaling skill. I guess Ice unit because Ice needs it

-NV Cloud and Zack (self chainer skills with a big Magnus skill like DK Duane and Big 2 hit LB) Lightning unit to match the Cloud Strife and Younge Hero Zack or Fire to match the collab swaps, and their magnus is a double Meteor Rain/Shots