If this is Peak Power Onslaught...the version who is able to leech off of Franklin Richards...then those who think Monarch has a prayer are out of their mind.
Prime's never ever been referred to by anyone who works at dc as precrisis. That's a faulty comparison and Superboy wouldn't hold his own or scar a precrisis being for life.
Prime wasn't even hurt and at normal strength levels he ripped him open easily. Onslaught has the power to rip his armor in two.
By the same logic Seid was superior to pre crisis yet was untouched by the crisis yet currently isn't anywhere near these levels. No writer writes him precrisis levels unless you think Superboy can scar precrisis beings with his heat vision.
Moving a planet isn't precrisis it's just someone who can move a planet pretty quickly. Precrisis is sneezing a galaxy away. Prime doesn't have any feats anywhere near this level of insanity.
The Hulks levels of strength are variable, the blow that opened up Onslaught was unquantified and may have been powerful enough to have done the same to Monarch.
Onslaught wins this, he has too many tools that he brings to the table, while Monarch can only rely on power. Not good enough when battling someone that can shape his own reality within his opponents own mind.
He moved enough Planets over whole sectors (the Universe) fast enough to change the center of the Universe without the Guardians noticing, and then it was to late.
As for the sneezing feat... I think it's not unlikely that the feat was accomplished because of the magical-powder of Mr. Mxy.
Except of this, he survived an Universe-Buster point blank... PC Superman was koed by less, a Solarsystem-buster point blank...
He operated on PC levels most of the time. Not the most insane ones but close enough.
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