Jayce, Hextech Visionary

When Jayce, Hextech Visionary enters the battlefield, create a powerstone token with "{t}: add
an amount of {c} equal to the number of powerstones you have."

Whenever you cast an artifact spell, choose
one that hasn't been chosen this turn:
• Jayce gains vigilance until end of turn.
• Create a 1/2 colorless Construct artifact creature token.