Who works with SOSP and LM..?
I dare to say...
Best options:
- Ronin Zabuza (swordsman, irremovable blind, defense decrease, solid counter to enemy SOSP)
- Rinne Sasuke (swordsman, irremovable paralysis, fear, solid counter to enemy SOSP but less reliable than Zabuza)
- Rin (healer, massive reduction to dmg received, undodgeable interruption to 3 targets up to twice in round - both requires 20 chakra but LM serves as battery there)
- Edo Minato (great barrier achievable as f2p too)

Decent options:
- Edo Nagato (CD increase, chakra cost increase)
- Teisho Mabui (immunity to interruption + 0 chakra cost)
- SSS Bee (immunity to interruption + extra standard)
- Halloween Kimimaro (swordsman, CD increase, mystery dmg boosting barrier)
- Summer Kakashi (massive dmg boost but reduction of defense / resistance)

after these, there are ofc Obito GNW, GNW Madara, Sage Kabuto etc... but those are more suitable for other mains as LM does not buff them directly (yet still works with both LM and SOSP)