The class would end and Goku would head straight for the old school house and wouldn't wait for Issei. Goku would burst through the door.
"RIAS, RIAS. I heard through Issei there was going to be a fight between the peerage and some Riser Phoenix." Rias would look shaken.
"Goku, I'm sorry I should have told you about Riser." Goku would say, "It doesn't matter if you have told me about Riser all that matters is that we win."
Rias would chuckle at Goku just wanting a fight. Issei would arrive after Goku as he would be out of breath. "Damn Goku you are fast." Rias would regain her composure.
"Goku the rating match is in three days. You can't beat him with three days of training." Goku would chuckle. "You know I'm hiding my power also I'm a God."
Rias would be shocked with wide eyes, "No you can't be a 'God' there is already a God." Goku would respond, "Maybe in your mythology as Goku would power up to kaioken.
He would start to levitate off the group as he Rias Gremory Peerage would be shocked. "You can fly?" Goku would laugh "Yeah I can fly but I best get going home just tell me to wait time I should be at the rating match."
Goku would train while still coming to school for three days. Despite not doing much Goku would still train but during one of his train sessions, a white circle with rituals would appear.
Women with silver hair and a big bust would appear wearing a blue maid outfit and silver eyes. Goku would sense she isn't that strong but he would hear her out.
"Son Goku I heard that you were fighting in the rating match. I do have to inform you that Riser is a powerful opponent and Lord Lucifer one of the Great Satans will be watching."
"So the devil will himself will be watching and also tell Riser that he will not survive him" Grayfia would nod and would leave in the same way she came. Goku would watch her leave through the portal. Goku would continue with his training.