WildPolarBear
The character's Hatsu works with En. I know that other methods cannot be used while using en (ken, zetsu, ten, ren). If it's noon, loki is at its weakest when using En. You can solve this case with oath and restraint. Therefore, with this restriction, there should be the ability to halve the use of En and use other principles such as (ken, zetsu, ren, shu). Otherwise it will be too strong.
??? I don't know why but I read this and it just does not comprehend in my brain but let me double check. You're saying to solve the restraint of having to use En, I can set a vow that his En becomes weakest at noon in exchange for allowing him to use other various forms of strengthen like ken, zetsu, ten, and ren? If i'm correct than it's good because I already planned on doing something similar.
tone down on the 'evil bad dude' personality moments, less is more in this case imo, and as for the hatsu, realistically it isnt all that, its too complicated, like is it being use in a way of 'i command my nen to put him in an illusion of whatever' or is it the mc just controlling the hatsu on the enviroment, which is how i read and understood the hatsu, this makes his earlier task of putting illusions on multiple people in order to kill eachother much harder, just telling your nen a command and then have it carried out by the nen saves time and is easier in the middle of a fight, the second one is needlessly difficult.