After that I'd work on improving the lands, focusing on mana-fixing lands that enter untapped since this is a 3C deck and our commander requires all 3 colors
Kestia was flavored as a minor character from Theros, and works synergistically with other bestow creatures, however small that category of cards might be
Keep in mind that you untap all your creatures when it enters the battlefield, not just what attacked, so any creatures with activated abilities can get extra activations
It didnt take much time for this dragon to start flying high
Amonkhet is my first exposure to cycling cards in Constructed, and Ive been very impressed with their power
If you like to deal with problematic cards as they come, this might be the artifact for you