Order Sol isn't an amp it's actually a downgrade. Order Sol is just a younger Sol with less control over his abilities going ham with a slab of concrete instead of Fuuenken
Having said that he made the Outrage, a weapon so strong he had to split it into 8 parts, one of those parts being Fuuenken which he later combines with another piece (Flashing Fang) to make his current weapon Junkyard Dog. For an example of how powerful the Outrage was Sol made a makeshift one toward the end of Strive with duct tapes and some elbow grease and it was strong enough to kill I-no who was universal+ at the time. When I-no asked why he would even make a weapon that powerful he replies with "because I could"
There's also the fact that him just existing is a threat to the universe. He carries the "Flame of Corruption" and his bitch (Jack-O) carries the "Scales of Juno." Technically, if these to things spawn into existence at the same time the universe experiences a hard reset however, while inside Jack O and Sol they're dormant. That being said Sol using Dragon Install has a chance to cause this to happen when he uses it so he's literally gambling with the universe when he does it.
He's also hard to kill since, at one point he goes back in time and kills his younger self (something I-no set up using her time powers) and instead of disappearing from the timeline like I-no planned he goes "lol fuck you" and continues existing anyway and thats not even considering shit like the master ghost.