The first problem that I personally see is the sheer range of abilities. Everyone else has a rather specific power. Ice, fire, not-dying, light, summoning, shadows, etc.

Samoth's abilities don't exactly do the dew here.

Rather than having a cohesive power with clear strengths and weaknesses, Samoth has a bunch of scattered powers all relating to a vague concept.

Quick list:
He can control gravity.
He's a master martial artist.
He reads The Art of War every day
He can communicate (and manipulate) with only a range limit.
Psychic blade, which honestly, is an ability by itself.
Telekinesis
ESP
Psychic constructs

There isn't much cohesion between any of this.

Why have gravity at all when you have telekinesis? Gravity doesn't even fit the mind theme - gravity is a fundamental force and _by itself_ is cool enough to warrant an entire core power dedicated to it with a bunch of sub-abilities supporting it.

Additionally, he doesn't really seem to have a weakness. I'm not talking about adding little weaknesses that nobody cares about, I'm talking about his inabilities. Usually, you can get a read on powers by thinking about what powers don't do. For example, Bak the weaponry girl.

Bak is entirely physical with a huge emphasis on ranged combat. Let's say, just as an example, a character could make a magical shield that reflects projectiles. Bak is at a huge disadvantage.

However, this is a good thing. Not every fight needs to be a fair and balanced duel where both parties can win. Sometimes, you just have to get shit on because it's a bad match-up. That's fine. Losing is fine. But what's more important that losing is learning to fight at a disadvantage. Bak could shed as much as she can to become highly agile. She can fire rockets at close range, trying to use the fact that she's covered in metal to survive. She can push her limits, and in effect, be forced to fight as an entirely different person.

If Ria fights Alto, there is no possible way for Ria to win. Ria relies on her eyesight to fight. Because Alto is a walking flashbang, Ria can only not be blinded if she doesn't look at him, making her powers useless. That's just how it goes sometimes. Ria, however, has an advantage against punch-mages. She can follow their moves enough to beat them.

Combat is always entertaining when a party is at a small disadvantage. You get to see an underdog come up and do their best. If the underdog wins, you can feel like they _truly_ deserved it. If they lose, you can see that they tried their best but still couldn't win.

Samoth's coverage is too high. He's able to: change gravity, use telekinetic attacks, have one-way-combat-communication, be a master martial artist, manipulate minds, basically have Ultra-Instinct, the ability to create psychic barriers, and he even sips some brain juice in his free time.

There's no way to fight against him, resulting in an empty stat-block that only exists to be a power gate: you must be this strong to win.

If you get close, he pummels with with martial arts. If you get far, he tosses shit at you and blasts you with brain beams. If you manage to try to overwhelm him, he still is aware about everything because of ESP. The only way to beat him is by being stronger, which makes for lame shounen combat all about yelling and friendship powers.

It's better to have a single open power, such as object creation, rather than a bunch of related powers that do specifically one thing.

As the great Kanye West says:

Everything I'm not, made me everything I am.

^{also everything relating to mind manipulation is absolutely horrible}