This deck is based on gaining life, specifically to trigger abilities by
Katra, the Devoted and
Cult Aspirant.
This is made up mainly of cards I have in my collection, and thus is on the budget-y side. That'll probably change as the deck evolves. A good early game usually consists of a turn 1 Cult Aspirant, and a turn 2
Sanctuary Priest, so that you can start building the Cult Aspirant by playing lands. In the absence of lands or other triggers,
Ancient Bauble works very well as a source of constant lifegain.
Water of Life is a cheap, fast life source, having Echo only makes it more dangerous as a way to trigger Katra. An unanswered Katra on the field by itself is often enough to take the game, but when it's not,
Colony Matron is a great source of life, triggers, and flying units.
All beefed up with general removal like
Deathstrike, and team buffs like
Xenan Obelisk.