His clothes just barely stand out in the freakshow that is the Heavens Arena competitor intake area. He is eagerly pointed to a line leading to a window where one of the receptionist will give him a form to fill out. 

You know what's harder to do than learning to speak another language by listening to people? Learning to read it without a proper teacher.

He can try to make a guess at the form's contents by familiarity with bureaucracy and studies of street and window signs and discarded newspapers but this is unlikely to make it clear.

He will endure the shame of getting back in line and telling her, "I can't read this."

Several of the people behind him in line will look annoyed but the lady will tell him where to put his age, name, and a signature saying that Heavens arena has no liability what so ever for anything including dyeing in fights and being defenestrated by security.

While Abyssal Fist is struggling with the form one exceptionally young looking entrant explains to his similarly young looking friend that this place is great because you don't have to deal with restrictions like in the Hunter's exam you just fight people and go up when you win.

He's twenty. He puts down 'Abyssal Fist' as his name - he cared enough about that to intimidate a now slightly traumatized librarian into finding synonyms for what his true title is until he found one that seems to flow in this language. He'll sign with just messier version of 'abyssal fist', since they don't use personal stamps here.

That does sound like an advantage. This seems to be closer to the no-restrictions tournaments than anywhere else he's seen. Hunter's exam, huh? That sounds potentially important.

"Abyssal Fist-sama you are #2045 they'll call your name on the first floor of the arena so make sure you remember it. Then please go ahead"
She isn't reading off a script but only because she has it memorized. There is a pretty obvious hallway she vaguely gestures towards.

Sure. Hurry up and wait.

...Actually he nonchalantly lurks in earshot of the kid who mentioned the Hunter's exam.

"Killua Zoldyck-sama you are #2054, Gon Freecss-sama you are #2055 they'll call your name on the first floor of the arena so make sure you remember it. Then please go ahead."
That is enough of a numbers gap that he should get going if he doesn't want to risk missing his fight. At least he got the names though.

Oh well.

He watches the fights leading up to his own, trying to judge how much he should hold back to be good but not absurdly good and hopefully not kill or cripple any of the squishy mortals.

This is actually kind of hard because there are 16 active rings and a huge level of variation since this is before any sort of filtering happens. The median person would lose to a non-cultivator with a few years of martial arts training or a lot of bar fights under their belt. The best person he sees would probably still lose to him in one hit, but is better than the others by enough if he extrapolates out the level of difference he sees in the under an hour of wait time then, well blindly extrapolating is silly but they probably get people actually at his level a few times a year.

Bullshit they do.

...Well. Actually he is pretty early along the path of a martial cultivator. It's not impossible that a mortal could have sufficient training and raw skill to meet him blow for blow if he's not using any techniques. Until they get exhausted after a minute or two of high intensity combat and he doesn't.

His first oppent is a ridiculously generic muscle bound tough guy who takes up what can generously be called a bar-fighting stance.

He holds back his strength and aims blows for places likely to cause pain but not too much damage. He deliberately holds still for a whole second twice, to let telegraphed wide swings catch him in the shoulder and pretend to be knocked off balance a bit by it. He still wins handily after a couple of minutes.

"Ok you can go to the 40th floor."
The referee has a small device of some sort that will print out a little ticket for him.

Just as his fight is ending 2055 is called. His ref has to talk over the crowd commenting on a little kid joining the fray. 

Either the kid is going to get destroyed or do something very impressive. He ought to watch on the chance of the second thing.

The kid takes up a very grounded, but otherwise not that great stance. He then fails to activate any anam or even anything that feels "different but similar" to Warden's cultivator senses. Gon then waits for his opponent to get close and pushes like he is trying to open a door. There is now a person shaped dent in the wall.

The crowd goes wild. The announcer and ref are clearly super impressed but not calling shenanigans. If Warden's hearing is good enough he can find out that the kid is going to floor 50.

Really? No anam at all? Nothing that possibly resembles spiritual energy or some other activation of power?

What about the kid's body, does it look noticeably different to the (stupid worthless tiny) flickers of energy that flow hither and yon all throughout the world?

Kinda, it separately looks like there is something very loosely related to anam latent but not exactly active and if his powers really let him examine flesh itself like the kid's physical muscles are not quite human and in fact are rather more efficient than would be expected at a purely physical level.

He can tell something is different about the boy's body. Without actually touching him and focusing, not more than that.

Maybe he's a local cultivator, whatever that means here. Looks like Heaven's Arena was the right place to go.

He goes to floor 40.

Cool his ticket will let him get an elevator as well as enough money to buy a drink from the vending machines. If he looks at all disappointed at this the staff will reassure him that the floor 40 fights pay out 40,000 Jenny. They will be smart enough to not tell him that this is a decent amount of money for a normal person and  small fortune for a hobo.

There is another line to sign up for fights. He can get in today if he wants, or come back latter if he wants to explore a bit first. If he does now he'll still have some time to observe fights but they'll expect him to stay in bullpen until he gets called.

He kind of needs more money. He'll watch for a little while just in case floor 40 fights are full of cultivators who can pop him like an over-ripe lychee, then sign up for another fight.

Nope, he sees a third kid (what is it with kids here) that is better than a non-cultivator kid should be. But even he is not as stupidly OP as Gon. According to the announcer, the kid is Zushi. Judging by Zushi's fight and the audience reaction it is both the case that Zushi would loose to Warden (unless he is holding back) and that Zushi is considered very strong by the standards of this floor. Everyone else is better than the average on the first floor but firmly in the range of non-cultivator who knows conventional martial arts.