Pokécharms

And the reason why Stellar knows you are children is because of how you talk on the internet. Not that difficult. Plus, that's just how he is.

Not all Megas are op such as mega garchomo and there not rare there everywhere even the anime says so
Are you sure your a Pokemon fan or what

Also some adults talk like teens and / or children

It's a regulation they use to keep everyone from having Mega Pokemon. Mega Stones and Key Stones are actually pretty rare and they sell for a lot (which shows how valuable and rare they actually are). The anime, sometimes the games, and especially the manga don't make this any easier, as they are not very realistic.

Plus, all Pokemon, if they mega evolve, are pretty powerful. Stats equate to nothing in a realistic setting, so Mega Garchomp realistically (if you take into account of Pokedex entries) can slice you in half and wouldn't recognize its trainer as its trainer and will attack anything and everything in a blind, pained rage.

I know some adults act like teens. Stellar has a Youtube Channel and he looks to be in his 20s and even states multiple times that he has a job. Also, what you say on the internet is what people are going to assume.

If you want to make yourself seem older, use proper grammar and spelling, or else everyone will think you are a child. That is your own fault that you can easily remedy if you get triggered over being called a child.

I'll give you information on that from the actual Pokemon Role Play Rules: https://pokecharms.com/threads/pokemon-role-play-rules.9451/

In it, it states that a Mega Evolution is painful, as the Pokemon's 'super-charged' state is too much for the Pokemon's body to handle, which is why most of the Pokemon who Mega Evolve don't remember their trainer as their trainer, even with the strong bond they had beforehand, as it sends them into a frenzy.

The strong bond is only there for the Pokemon to regain control of itself, and the transformation itself still needs training to master.

The catalysts for such (Mega Stones and Key Stones) are super rare, and can not be idly found. This is all in the lore of the games, and as such, is a part of the reason why we have to ask permission for Mega Evolution.