Classification: Rogue Kaiohshin (10th universe, future), Fusion || Abstract/conceptual being
Threat level: Celestial || Celestial+
Physical strength: At least universe level striking || At least universe+ level, likely low multiverse (became a conceptual part of reality)
Attack potency/Destructive capacity: At least universe+ (far stronger than Future Zamasu or SSR Goku Black) || At least universe+, likely low multiverse (was affecting other timelines)
Durability: At least universe+ (Super Shenron/Zarama granted Future Zamasu immortality, plus Black's body should grant continuos zenkais. However due to Black's body not being immortal, Merged Zamasu's body is unstable and can be eventually be taken down. Took Vegito's Final Kameha meha wave and survived.) || At least universe+, likely low multiverse (Goku, Vegeta and Future Trunks combining their attacks into one didnt even affect Zamasu)
Speed: At least TransUniversal+ || Unknown, likely TransUniversal+, possibly higher (nigh omnipresent on at least a universe+ scale)
Intelligence: Genius. A much more experimented version of Zamasu, fusing the qualities of both normal Future Zamasu and Goku Black.
Stamina: Nigh-limitless. Not only does he posses a body with enhanced saiyan traits, he also posseses a immortal body, making stamina borderline not an issue for him. However due to Black's body not being immortal, Merged Zamasu's body is unstable and can be eventually be taken down. || Likely limitless. Apparently became a part of reality itself.
Range: At least planetary with Ki blasts, otherwise melee || At least universal, likely multiversal
Standard equipment: Potara earrings, time rings || None
Key: Supreme God || Infinite Zamasu/Concept of Justice