Warden of the Inner Sky

As long as Warden of the Inner Sky has three or more counters on it, it has flying and vigilance.
Tap three untapped artifacts and/or creatures you control: Put a +1/+1 counter on Warden of the Inner Sky. Scry 1. Activate only as a sorcery.

The Lost Caverns of Ixalan

The Lost Caverns of Ixalan Promos

You can tap any three untapped artifacts and/or creatures you control, including Warden of the Inner Sky itself and other creatures you haven't controlled continuously since the beginning of your most recent turn, to pay the cost of Warden of the Inner Sky's activated ability.