Every time I level up, it says I gained 8% health, shield, etc at the bottom of the screen. so I did some math, and found that my stats would then double every 9 levels. this seems like an insane amount, so tell me: is this true?
The 8% works off your base stays only, so does not include arts or ET upgraded. Yes, every 10 levels your base stays are almost doubled (80% not 100%). Basically, it is another percent increase like arts give.