Night_Builder
Have you considered getting the spirit ring from the devil god demon might be cliché but talent, bloodline and attribute wise its atleast in the top 3 to 5 among all spirit beast. With it you could create a darkness/ultimate evil core and time and space core and even acquire its bloodline and its attributes which mc could manipulate and even mix with his poison like that one mc from Soul lands author's other work.Also with the beast ultimate evil you essentially have one of the greatest attributes since evil can be attached to anything to make it really strong, prevent healing and bieng extremely hard to cure and fight agaist unless you have a ultimate attribute and thats only against regular evil attributes, look at soul land 2.and Ultimate Evil I would only expect the ultimate light or the perfect seraphim spirt to condent against after all the evil comes fro. the Blood of the Evil god who is a god king.