GhettoGodzilla

I mean for Domain Expansion it would be pretty simple no? Straight up blood bending (like from Avatar). Something like where the domain is a lake of blood with infinite amount of blood and he can control ALL blood, even the blood inside an enemies body. Might be a bit too busted though. As for a Maximum Technique. Like some others have mentioned, Raizel from Noblesse and his Blood Vortex/Blood Field, where each blood drop becomes as sharp as a blade.

So sort of like Wei Zhijun from Darker than Black? Or could he do it more like Nezuko from Demon Slayer, although that is more igniting/exploding the blood, could be another usage though.

This may not exactly be true in the Harry Potter-verse, but generally in stories with magic, a wand or staff acts as a focus and an amplifier. Without a wand, the necessary focus can probably be achieved with training, but the magic amplification probably cannot. And as such wandless magic is probably weaker and less potent. A workaround to this would perhaps be the usage of emotion, like with accidental magic. If the MC could control his emotions and use them as an amplifier eventually he could have equal output with or without a wand.

Good on you Author for acknowledging this, not many other stories does that while having similar starting settings. Some MCs just start doing Saitama workouts on deserted islands without any ramifications...

I dont think 30 is middle-age lol, more like 50-ish.

Hmm you are right, Ko is using 100% of Nen into an attack. But actually we are both wrong. Ryu is the actual term for using Nen around the body and concentrating it in different parts.

I think you mean Ko. Although Ko and Gyo is essentially the same thing, Gyo is just Ko focused on the eyes to see Nen. Ko is focusing Nen on any other body part.

Good choice. He is waaay to weak right now to scrap with shinobi, even genin will probably kill him under a second. And he might be an excellent liar, but in front of shinobi his deception wont hold up for long.