Team comps for Fuuma?

He works well with Jack. I prefer Buster teams so I mainly use him to give Herc or Jalter an evade.

I mean the whole point of a star generator is to pair them with units who capitalize well on crits. Otherwise he works well with literally any other assassin. If anything, I'd say he syncs best with Serenity Hassan since she likes her debuffs too. Stheno and Phantom work well too since the chance of their charm success increases slightly.

The thing is, Fumma has low attack and a weak NP, so putting him in the role of damage is a poor utilization of his kit. He wants to be generating 50 crit stars so that someone like Jalter, Gilgamesh, or Raikou can deliver devastating crits on the following turn.

Equip Crit Magnet CE to Fuuma, if you want him as your Crit DPS.
For non-Crit reliant. NP damage up, Quick up, or combined 2 in 1 CEs would works.
Non-Crit reliant team set up is good for him since his star weight is low.
But best if he is the main Crit star generator in the Crit teams, not the main DPS.
I found it pretty easy to make a good team for him.
Also if you have tried making some 1-3 stars servant team comps, you pretty much can figure it out to make a good team for Fuuma.

Fuuma is your husbandos then, it's fine mate he still works good outside Crit star generator and party Debuffer. Since you have already told u don't want him to be paired by Gil or etc.

For me, as one of the guys that defeated the entire Camelot using 1-3 stars like Fuuma he is enough vs tough rider enemies waves/bosses or even killing some tough zerkers enemies.
After defeating Babylonia with my main rosters/acc soon, after that i will proceed to use my 2nd acc to clear Babylonia too while limiting myself to using lowstar and Bronze servants.

Some team comps for him :
Fuuma + Georgios + Hans
Fuuma + Asterios + Waver
Fuuma + Cursed arms + Mashu
Fuuma + Georgios + Mashu

For more advanced ones, Fuuma + Georgios + Waver + Mashu + Blackbeard/Caesar + Og Chu/Chu/any anchors.
Use all of your Offensive buff to Fuuma, swap him to the back then try to keep your buffer alive, use your tank as a boss ''punching bag'' then after one/all of your tank is dead, enjoy your broken Fuuma damage.

For more simple combos, Fuuma ( NP battery CEs ) + Mashu + Waver + Blackbeard/Caesar.
Buff Fuuma then Boom !!!, take boss hit/NP using Mashu, waiting skill CD, Buff then Boom !!!
again till the enemies defeated.

Preferable MC is Chaldea Battle Suit, it can provide lots of tactical strategies for a lot of FGO masters.
It's still and example of the Bronze and Silver servant usage, it's gonna be far much more stronger if you use Gold servant in there.

That's it, maybe it will be a little help to you.
About the team comps, it's stil up to you as an FGO master.

Pair him with servant with high star absorption billy, ushiwakamaru, rider kintoki
And hans as an support
Or waver to combine his first and third skill with waver np, i personaly pair him with waver with 2030 from friend and nyanta equiped with glory is with me for constant crit team