Instead of Goku coming to sparr Zamasu, Superman Prime One Million wins and Zamasu thinks all humans are violent and makes it his goal to kill Superman Prime One Million.

Zamasu meets Future Zamasu Goku and after he wishes to be immortal they fuse with the potara. Zamasu is now immortal and has the heart virus to infinitely increase in power without the need of Zenkai’s but the heart Virus. And IF he were to have a Zenkai, his power increase would be insanity.

Zamasu decides to use the other time ring to find Babidi in another world due and gain the Majin seal which increases his power by 1/3

Zamasu masters Goku’s Kaio-ken and due to the Rose form being SO calm. He can control the Kaio-ken Goku used against Frieza. He also has gained zenkai and Heart virus power after his fight with trunks.

Now, according to the Screwattack video Superman x 3 sundipped was equal to Supersaiyan 4 Goku.

Superman Prime one million on the other hand was stated to have spent 15,000 years in the sun. In the movie All star superman after lifting quintillions of tons it was stated that supermans increase in power is not doubled but increased by 2 times for every year he spends.

Calculations

superman = ss4 (According to Screwattack 1)

ss4 = base form god ki vegeta / copy vegeta vs ss3 gotenks

ssg is 50 times stronger than ss4

Therefore

ssb = x60 ss4 (ssb easily 10% stronger than ssg)

ssb = x2 by the black saga (same zenkai and training)

ssr = x2.5 ssb (able to defeat an enraged ssb goku)

kaio-ken = x20 (maximum potential in the frieza saga)

majin seal using the time ring to find babidi x 0.3

zamasu potara fusion x 0.2 (Zamasu himself is that increase + immortal)

x 0.1 Zenkai + heart virus increase after fighting trunks

0.3 x 60 x 0.2 x 2 x 2.5 x 20 x 0.1 = 10,300 x screwattack superman

SP1M = 30,000 x screwattack superman (using the Allstar film increase)

If Zamasu becomes stronger he will win with constant Instant Tranmission and his sword saber since every hit he does weakens prime and because of it constantly being faster than him with IT and destroying suns with instant galaxy busting blinks which will weaken prime one million. For every second SP1M wastes thinking about creating a sun. Zamasu gets a hit. Zamasu is also immortal. SP1M was hinted to have wrestled gods and many hints indicated he isn’t immortal in his fights. Also being Omnipotent isn’t immortal.

Zamasu only needs a x3 increase to win.

This is what a 3 x difference looks like

www.youtube.com/watch?v=ENTtZD8Riig