It's been six months so far and Diesels grown a lot stronger thanks to all of the extreme training. Before he had trouble carrying the carcass of the first dinosaur he killed, but now hes able to carry two that size with no problems, not bad for a not yet five year old.
He never did fully understand how exactly to train to unlock haki because the manga never really went into detail on the full training regime. So he just made his own based off what each kind is supposed to do. Dodging logs swinging around while hes blindfolded and has earplugs in to try to cut down on his senses, and running through the forest like that as well to try to awaken observation haki. His way of training for armament haki was actually something martial artists have done for thousands of years on earth. Punching, kicking, elbowing, and kneeing something hard to toughen up the skin a bone of that area, some also had others attack their bodies hoping for the same result across their entire bodies.
The only difference between them is Diesel is using a cliff he found whereas those of earth would use boards, bamboo, and other such things. After he reaches the appropriate strength hes planning on using his fists to carve out boulders to roll into his body to strengthen it. If that doesn't awaken a dormant power meant to protect a person from harm he doesn't know what will.
With conquerors haki he wasn't sure how to train for that, so after he was done with his physical training he ran simulations in his mind trying to use his will to suppress and intimidate others. Needless to say he'd never tried to attack someone with his will before and felt rather stupid trying, but kept on anyway since this was a must to be the strongest here. The sooner he unlocked it and got it under control the sooner he could start trying to coat his fist with it.
Later on when he was dodging logs, just as he was about to stop and move on, he felt something click like he comprehended something. He then immediately messed up and let a log hit him into a tree, but he wasn't even mad as he could feel his immediate surroundings like a blurry 6th sense.
After about another hour of getting used to it he could make out the different animals and insects around him and oddly enough it felt natural. He didn't get overwhelmed trying to use it which honestly suprised him but he wasn't gonna complain and immediately started reworking his training schedule.
A few weeks later as he was looking for food he came across a small cave with what looked like a baby wolf that was about to get eaten by a huge snake. Now he would normally let nature run its course but he has a soft spot for dogs (even though its obviously a big ass wolf pup) and refused to let it die here. So he kicked the snakes tail to get it to turn around and punched a hole through its head.
After checking on the wolf he realized it was all skin and bones. Looks like its mom probably died out here somewhere and hes been alone for a while. Just like people the animals of this world are tougher than on earth yet it still looked like that.
"Little dude I'm Diesel I think itd be best for you to come stay with me. Let's get some food in you real quick." Diesel said with a smile. Picking up the scared pup he returned to the tree base with the snake dragging behind him. Turns out the pup is a boy so he needed to think of a manly name for him. He decided to ponder on it and time moved on.
The first year of his training has just ended and he had made quite a bit of progress. He hadn't unlocked the armament or conquerors haki but he had made great strides physically and he guessed he was probably around Rear Admiral level. However what he was most excited about was that after almost six months the little wolf had finally excepted him and they were now good friends, he was even trying to help him unlock haki the same training Diesel did, so he had a training partner now. After much deliberation he decided to name him Fenrir after the strongest wolf of mythology.
One of the things Diesel liked about this world was how smart the animals are and Fenrir is no exception, so they started working together to bring down bigger and bigger animals. They didn't need to given how strong Diesel is even the strongest beast in the forest, a huge strange looking bear like thing, was only on par with him in terms of strength and stamina. That said he was planning on taking Fenrir with him on his adventure with him so not only did he need to get much stronger but also learn how to fight effectively side by side with Diesel. At the very least he hoped Fenrir could grasp armament haki before they left as it would make him far more durable in battle.
Because of his rising strength Diesel would severely handicap himself each time while he was hunting or training so he got the best effect he could. By using some vines, to attach some weird ridiculously heavy rocks he found after punching into the cliff face, to his arms an legs. He was sure he looked stupid and there were better more efficient ways to do the same thing but he would need to go out and risk running into someone stronger than he currently is. He decided to wait to leave till he thinks hes strong enough to kill an Admiral just to be safe.
This world is basically a battlefield with pockets of peace scattered hear and there so he needs to be careful for at least the next 10 years or so. Especially since, even though he used a part of it once, he still hasn't fully activated his devil fruit. He remembers that the ghost rider is, according to the comics basically immortal, so he doesn't want to try until hes fully grown just to make sure he doesnt get stuck as a child for decades.
'Nose to the grindstone and keep moving forward' he thought 'trainings just begun'.