You Pokemon are totally hacked but...It’s fine. I myself use hacked Pokémon online. The reason is:
If it’s poorly hacked, it won’t be allowed online and hence you won’t need to worry about getting in trouble for using it.
If it does work and is accepted online, then there is no problem as the game hack check approves it as legal.
For a play through(no WiFi) go ahead.
I got around a hundred hacked Pokémon from Mitsuki.TV and they all work (excluding the Matshadow).