These three groups of weapons are the most used weapons by battle sage monkeys and will ensure that he will have a wide array to choose from.
He used a dagger in his past life because of its lower requirement for technique and its reliance on agility rather than strength. But the dagger is more suited to assassination and will be ill-suited to cutting off the necks of a hydra. He is sure the familiarity with it and his speed will allow him to slip by the hydra but he doesn't want that. He wouldn't be able to challenge himself and he wouldn't be able to continue using the dagger when his divine ability awakens. Battle sage monkeys don't use daggers.
He prefers the spear because it is like an extended dagger. A blade on a long stick. It will also allow for quick burst action just like a dagger and it will have a longer reach. His mastery of the dagger will be useful to a small extent. The problem is that that long reach of the spear might prove counterproductive against the Hydra as he tries to slip through its defense.
Still, he has to choose a weapon and he wasn't going to use his hands. It will be much better to choose something he is more familiar with and learn to adapt to it. So he chose the spear.
He left the safe zone with his gait sure and filled with confidence. He had been able to harmonize with the water earlier because of the repeated adjustments he had made to his body. Harmonization isn't something new to him, he had been able to achieve it relatively easy as a high elf due to his affinity with nature and mana. You would think it should be easy to do again but it isn't.
One of the major reasons is that he never tried hard to achieve it in his past life, it came to him naturally. The other reason is that his soul is too powerful for his body so his mind simply dominates his body. It is difficult for them to act in sync. But it finally happened after his body didn't require him to police it when the movement itself became a reflex action. He achieved it due to the rickety pillars. Their unstable nature made the fleet foot technique second nature.
That's why he isn't scared of water challenges anymore. He is confident in overcoming whatever might be thrown at him.
"Let the weapon become an extension of your body." He said as he caressed the spear.
He didn't know the meaning of what he said but he had an idea about it. He had heard the statement from other weapon users in the past. He was never a true weapon user, he was a killer. If his powerful mind couldn't overwhelm his opponent then he would add the sharp edge of a dagger into the mix. That usually gets the job done.
He is usually outclassed in close combat but the innate grace and agility of a high elf always helped him. That and trading blows because it doesn't matter who is the better-skilled fighter, only the person that dies first matters. He survived to become an Origin god because he always had the last laugh. But now he wants to be able to laugh last better since he won't be going the same route as in his past life. There won't be near-unlimited regeneration to count on.
He soon came upon the hydra and began running around while observing it for any signs of weakness. Harmonizing with water hasn't made him able to stand still on the surface of the water, at least not yet. That will happen when he becomes a mana entity.
While he was watching the hydra he noticed that another head was rising out of the water. It is still unstable for now but he knew it will solidify into ice if given time. He wanted to collect information on attack patterns but more heads will make the already difficult challenge too much for him. So he dashed forward and brought his spear forward.
He didn't know much about the spear but he had some common sense about it. He knew that the blade of the spear must be pointed toward his enemy. He also knew that an enemy must not be allowed to get within your guard and to always use the other parts of the spear too. That's why he approached the hydra with the spear extended forward and his two hands gripping it.
The hydra had reptilian features. Its pupils were vertical and it has bluish-white scales that match well with the surrounding water. The necks of the hydra protrude out of a hole in the ground on the beach. The hole is behind the finish line so he doesn't have to pass the hydra exactly, it is more like he had to reach it, all the while with the hydra trying to stop him. He will only pass the choke point when he reaches the 20m glowing line right at the base of the Hydra's neck.
The Hydra attacked him. It attacked with a single head. The attack speed was very fast but it wasn't as fast as the tongue attack of the titan frog. He could see the head of the hydra move forward to try and bite him. He could see it and he could react enough to do something about it. He dodged by hopping to his right. There was another head just behind the first one, he transformed his dodge into a roll. Then he fell into the water. Another hydra head bit into him underwater and so he returned to the safe zone.
He slapped his forehead. "It isn't the ground. How could I forget such a thing."
Only the soles of his feet can utilize the fleet foot technique. The rest of his body can't, that's why he sank when he rolled out of the way of the second attack. It was an instinctual movement on his part to evade the second attack. He left for the second run to engage the hydra again. His gait wasn't so confident.
This time he anticipated the attacks. He watched the movement of the necks in order to predict them. It was just that while he could anticipate the first and the second attacks, he couldn't react well enough to resolve the attacks. He doesn't have the full use of his ability on the water surface. The worst part is that the heads can also attack him from behind even if he had succeeded in dodging it earlier. The attacks came from the right and left, from back and front, from up and from under the water. So the water inhibits his performance but amplifies the hydra's attack options.
He had a plan of attack after understanding most of the parameters of his situation. Dodging the head wasn't working and he wasn't equipped to parry them. The only plan he could think of that would work is to cut off the heads, cut them fast and move fast. He plans to move faster than the heads can regenerate or at least that's what he planned to do.
He started another run with that plan in mind. But a blitz attack is easier said than done with the spear. The spear turns out to be unable to cut the heads fast enough because it is more suited to thrusting. The diameter of the necks is 3 times the length of the blade of the spare. There's no way a short blade like that can cut something that thick. Either that or he is very bad with the spear. Anyways, he stopped trying to execute that plan after 10 runs ended with failure. The hydra would just regenerate the small injuries he was able to create to it.
So he moved on to thrusting. He was inclined to believe that he might not be so good with the spear when thrusting didn't work either. Thrusting required power to fully penetrate targets and cause damage. His attempts with thrusting ended poorly. He always lodged the spearhead into the skull of the hydra and can't remove it. So he either has to let go of the spear, which is a bad idea, or hold on to it and be swung around like a puppet.
Whatever damage he can create to the head with thrusting is quickly regenerated by the hydra. The hydra is too big to use his spear effectively. Even when he uses a full-powered coiling dragon technique to fuel his attack, all he created was a deeper hole in the hydra's head. The deeper hole will kill the hydra head but he wouldn't be able to pull the spear back before he is annihilated. In the rare times that he succeeded in pulling out the spear, the hydra's head will regenerate quickly enough to render his effort useless.