UW Kefnet (Pioneer)

This is a buildaround list of God-Eternal Kefnet, trying to maximize on its triggered ability by using spells that can be used both when the trigger happens and then have impact later. It is a control deck that uses the ability to take over the late game.

Thassa's Intervention and Supreme Will gain card advantage with the trigger and can be used to counter spells or gain even more card advantage. Unsubstantiate can return creatures with the trigger and then soft counter spells or return more creatures.
Blink of an Eye deals with problematic permanents, and with the trigger it is very easy to make it cantrip in addition to still having it in hand.

The cards with cycling (Renewed Faith and Hieroglyphic Illumination) help guarantee land drops in the early game, stabilize life totals and card advantage with the trigger and can also trigger God-Eternal Kefnet a second time each turn cycle if they are cycled on opponent's turn (this last part also includes the Irrigated Farmland).

The Mystic Sanctuary puts spells that trigger the god on the library, and is the reason that there is so many island in the deck, including the nonbasic duals.

Declaration in Stone is a very good removal spell that can exploit the trigger, even casting it on opponent's turn if cycled into.

As for the sideboard, I've put cards that will help in different match ups and still continue the plan of the deck, but I haven't tested so I'm not very confident about it. The setup for the main deck is also in part to make the sideboarding easier, I prioritize the 3-offs, which are the most match up dependent. Renewed Faith is only good against aggro strategies, and Cavalier of Gales isn't very good against fast strategies.

I hope you find this idea useful, and don't hesitate to make constructive comments on it.