Saitama launches himself in the air and gets right in God's face with everyone else on Earth gone he doesn't have to hold back so now it's time to let it all go.
killer move serious series serious punch.
Saitama punches god so hard in the face that
it makes the entire planet shake. God is sent on the ground, with Saitama grabbing his head and sliding his face across the entire continent like rubbing sandpaper on wood.
Uses even more strength as he picks up his head and throws him across the entire solar system with God's body slamming into a planet far. God gets up like it was nothing. Saitama can be seen landing near him as he launched himself from earth.
God- "not bad strong one".
Saitama- "shut your mouth..."
At this moment god has begin drawing in countless rare minerals from the atmosphere. After decomposition and reconstruction, God gained armour stronger than Graphene. Graphene is the strongest material on earth. 200 times stronger than steel, and you'd need the weight of two elephants to break through graphene. God puts an entire layer of armor around his body to protect himself from Saitama's punches.
God- "shall we fight seriously 3rd dimensional creature?"
Saitama- "finally a worthy opponent".
God opens his face and shoots out a massive laser beam to which Saitama barely dodged and destroys an entire planet nearby.
Saitama- "just what the hell was that!!"
God- "Even nine dimensional beings cannot defeat me. Among the multiverse there are Gods with lower or higher dimensions with powers you cannot even begin to comprehend, for Me any dimensional being is a mere dust".
Saitama- "are you done with all this chitty chat".
God- "the destruction of 3rd dimensional beings is quite simple. One method is to decompose all organic matter I command. They will turn into 1 dimensional being like they never existed in the first place."
Judgement
Every living specie on the unknown was beginning to turn into dust, all except Saitama who was unfazed by this.
Saitama- "forget your little tricks and fight with me by your bare hands."
God- "fine... lets finish this".
As God goes for a punch, Saitama winds up his own and as their punches connect the entire planet is destroyed. The fight between the two disturbed the universe. When we see the two, Saitama could feel pain for the first time in years. God's body was completely eviscerated. He began to regenerate his body in a mere second. Saitama held his arm for a second to make sure he could still fight.
Saitama- "it's the first time I felt pain."
God- "you can still keep going?... well then don't hold back."
he sends Saitama to a fourth-dimensional Spacetime array where time will revert continuously with Saitama's body reverting back to how it was before his training.
God- "Fool!! In this forth-dimensional space-time array, time will continuously revert, not even once has an organic lifeform been able to escape this realm before being reduced into atoms. COMPLETE DEATH!!"
After a few minutes Saitama remained in his tracksuit but his hair growing.
God- "... strange dimensional lifeforms would have already been reduced to dust... but this one...
Saitama- "oh I get it... you're playing Tetris! King and I used to play that for a while, but that game made me dizzy. Overtime I learned tricks like placing the blocks in the centre but the most important thing is to be fast. SPEED IS THE KING"
Saitama began to get ready for a sprint. "Alright let's try this-"
Serious sprint
In an instant Saitama surpassed the speed of light and broke free. When Saitama broke out, he uses consecutive normal punches and eviscerates God's body yet again.
God- "you don't have a chance!! ArghHH...! IN THE MOMENT YOUR FIST SLOWS DOWN I'LL TRAVEL TO THE EDGE OF THE UNIVERSE AND REGENTRATE IN NO TIME.
God sends a massive punch into Saitama's face as he appeared behind him. it caught Saitama off guard as he was launched into several planets. God then grabs Saitama by the head and throws him to the core of the current planet they were on.
Saitama (serious)- "am I losing for the first time".
Saitama jumps back up and is ready for round 2.
Saitama- "you might be the first opponent I dreamed to fight".
God- "dream huh?"
God begins to raise his hand as he reads Saitama's memories and finally finds what had been looking for. He summons creature who gave Saitama his dream fight. Subterranean.
God- "kill him" pointed at Saitama.
1000 Subterraneans jump to attack him, and Saitama proceeds to expertly avoid their attacks, but then, all 1000 Subterraneans join their attacks to strike the hero downward. Saitama holds his elbows up to defend himself, but the force of the attack is potent enough to sink the planet down. Saitama's eyes flash with rage, and the hero sweeps the Subterraneans' feet from under them. He follows up with a loud shout and punches all of them, killing the monsters instantly.
Saitama- "THIS IS A REAL FIGHT!!"
God- "Behind you".
God appears behind Saitama and kicks him like a football launching him into space. Saitama uses a serious Fart to give him enough momentum to land on a ground instead of floating through space. He lands on a moon and sees God Infront of him. God proceeds to torture and assault Saitama none stop. Saitama was losing heavily.
God- "you don't get to choose how you die."
He then stabs Saitama into the stomach with his finger and throws him several miles away.
God- "once I'm done with you, I'm going to kill all your other friends and rampage the whole multiverse!"
Saitama- "Gahhh... *coughs blood* over my dead body".
Saitama was punched yet again but this one was different. It almost killed him.
Saitama POV- "should I just give up... after all I never wanted to do this hero stuff for real. Do I even have a hero's intuition... sure doesn't seem like it".
God- "you can't defeat me I'm a god".
Saitama- "AND I AM... ONE PUNCH MAN!"