As I'm sure you've noticed by now this has absolutely nothing to do with the original dragon ball z plot. J
Kaioken level 150…level 175…level 200…he just kept getting stronger.
Israel was relentless, he pushed Goku to the edge and over repeatedly, everyday first there was combat and then there was ki. It was starting to wear on Goku now and yet how could he deny his training or ask Israel to step it down when everyday his kaioken would leap up a level or two. That's not to say that he wouldn't mind a day of or something, combat training was the most dreaded part of the day, and whenever it was over and ki training began Goku would let out a little sigh of relief, his mentor showed his relentlessness during these times best, a constant seeming endless barrage of attack Goku would dodge, block, sidestep and avoid him to the best of his extent, his muscular became very lithe with this training and he could enjoy the feeling of a new ease of breathing and a spring in his step, not that he was actually given any time to enjoy it. After the usual regime of running and pushups and whatnot Israel would engage him in fierce combat, he passively gave Goku insights to new techniques, new power and most rewardingly, improved coordination. Goku could understand the need for mental and physical training but why it had to be so extreme was past him, some days he would try to attack Israel, helping him work on his offensive techniques while on others his defense was trained. He had yet to land a hit though as Israel's agility was extra ordinary and beyond his ability to overcome, if he moved like water than Israel moved like air, and then when he was finished (finished usually the point where his muscles were too used up to withstand any more abuse) they would begin ki training. Israel had taught him many new things he could use his energy to do other than far more sophisticated and perfect clones now he could read aura's (halos of energy around living individuals that told a lot about the individual's respective temperament).
Israel had developed a new type of resistance training for Goku. He would create a deflective shield that Goku would strike with an attack. In fact, it was more than just one shield, it was many layers of shields that would only break when Goku's attacks had reached a certain intensity, There were ten shields in all and Goku was still on the third one, his Mahar was rapidly becoming his favorite attack, not only was it highly powerful and destructive but it was also simple to use, Goku simply collected his energy in the small space that he made between his hands and shot it out in the form of a colossal ball. It was red with a pinkish tinge in color (Goku was learning that the motive of the energy gave the energy its color, healing energy for example, was blue) and flew towards the walls with only a slight whistling sound. The wall held the Maher pushed against the wall for a brief moment and then whistled its way back to Goku; the walls were deflective to anything too weak to shatter it. Goku would grab the hurtling ball of energy and hold, gradually the ball would grow smaller and smaller until it vanished into a flickering pink wisp. Then Goku would sit on the ground, catch his breath and try again, it was the day he reached level 300 that he managed to shatter the fifth wall, the day he reached 400 he managed the tenth. This might seem odd to you but as I said kaioken is exponentially progressive. Not to mention the fact that using the Maher every single day went a long way to making Goku's attacks stronger.
Now that he had managed the ten walls Goku was fighting his angelic mentor once again when it came to ki training. He was dodging and shooting energy at the same time, and he was not always successful in the former and almost never in the latter, when a blast of energy from the opposing side hit him, he would have to fall back for a brief rest, and because most of Israel's attacks were of the same power standard his ki training lasted only until he got hit two the three time. Yet as he climbed towards level 500 he began getting more positive results, he even managed to land a hit on his mentor the fateful day.
After what felt like months of training he had reached level 500, he had been training for a year with Israel and he certainly welcomed the milestone of power, he attacked him with a Maher that day, moving fast he managed to get a good vantage point and strike, due to the time restrictions it was not his best attack but his power and expertise had grown so much that the five or six shots Israel managed were cancelled out by Goku's strike and the blast hit the angel full on, when the dust cleared Israel was on the ground panting. Even in his combat sessions Goku was rapidly becoming more and more his mentors match; he would manage a few hits and Israel starting needing rest time as much as Goku. Recently however Goku had been feeling stretched, as if his limits were starting to get pulled, apparently Israel knew this too.
The day after he had reached level 500, he woke up to find Israel sitting in the ground. What surprised him thought was that his master gestured for him to come and sit down…it was a first.
Israel told him he had the day off, Goku gaped at him like an idiot until the angel explained.
"I have exhausted my usefulness to you my friend. Soon you will shed this body and evolve into a much more powerful form once that happens you will be out of my league. I have done my duty now you must do your, don't let me down." His words were accompanied by a flash of beatific white light; Israel was nowhere to be seen.
That's it mates…did you like it?