First ones level up

Do the first ones level up?? If yes how?

I remember seeing a thread a loooooong time ago about it, and yes they level up, (unless the guy used photoshop of course :I) but I’m not sure exactly how, since most of my first ones are S+ and I use them a lot, but are still “Level 0”, so I’m really unsure of this myself.

Only there rank levels up they have set stats