After checking in with my friends yeah uh…Spawn is not to be underestimated. Base Spawn unironically and solidly can get to Outerversal(More Below)

Spawn was able to shake all of hell with just his battlecry and this isn't hyperbole btw his scream actually did this physically

Hell as a cosmological place transcends the fundamental concepts of logic, space and time and reality, existing beyond ideas and physicality.

As Divine Spawn, and once he ascended to the same level as the Mother of Existence, Spawn transcended all of this and entered a state of being infinitely above what hell and heaven can reach, as well as transcending above reality to reach the level of being one with creation itself, which contains infinite higher levels of existence, so Divine Spawn can reasonably be put at high outer.

Also he's constantly growing stronger as every heartbeat literally multiplies his power by a hundred.

TLDR: He’s on par with Ghost Rider in strength.