You were an elemental master, but you didn't want to show off like those ninjas, so you've never shown yourself. But someone else clearly somehow found out about your elemental power.

You were walking down the dark streets of Ninjago one day when you felt the current of the wind changing behind you. If you hadn't  been fast enough to get out of the way, you would have been hit by none other than Lord Garmadon himself.

“Give me your elemental power now, or otherwise you leave me with no choice but to take it forcefully from you, and it won’t look good for you.” He spoke before getting ready to attack again.