This is a BUG land ramp deck built around cards like
Omnath, Locus of Rage
and Dragonmaster Outcast. The also has an elemental subtheme which utilizes Omnath's triggered ability, allowing for burn without having to rely on combat or opponent's removal to close out games (but with Omnath out and a couple of landfall triggers, it's pretty rough to come back from).
The Ramp:
Embodiment of Spring
is a slow version of Rampant Growth with a defender body. Can be useful to stave off aggro in early turns and can be used in combat to remove damage for lifelink and such. The self sac ability also triggers Omnath.
Atarka's Command
is a toolkit card that helps keep pressure on the offensive, ramp lands from hand into play, and even fizzle lifelink which becomes relevant against decks with themes such as allies or esper dragons with Foul-Tongue Invocation.
Natural Connection
+
Nissa's Renewal
provide raw land ramp. Both one-of, they provide the extra boost often necessary to outcurve other decks. Both are rather expensive and could be adjusted or removed for better cards. The life gain on Renewal is something to consider, especially against aggro.
Value Engines:
Temur Ascendancy
is the crux of the deck, bringing it all together. Provides both card advantage and board pressure with haste creatures.
Whisperwood Elemental
is great at getting extra cards onto the field, and provides protection against boardwipes. The self-sac ability can also trigger Omnath.
Planeswalkers Kiora, Master of the Depths
+
Nissa, Vastwood Seer
+
Sarkhan Unbroken
each fill a niche. Nissa helps meeting land drops and provides card advantage when flipped. Kiora and Sarkhan both provide extra mana with their plus abilities and aid in board position with their minus. Sarkhan also provides an aerial presence that is lacking in the deck save for an active Dragonmaster Outcast.
Greenwarden of Murasa
is an elemental that essentially acts as 2x Eternal Witness. Also an elemental with a decent body. A 1-of that provides a bit of extra redundancy for other cards.
Finishers:
Omnath, Locus of Rage
is the top end of the deck, while Dragonmaster Outcast are cheap threats that by themselves can win the game if not dealt with. Omnath at 7 mana is a bit bulky to be a 4-of, but Dragonmaster will often become a lightning rod for removal and thus is often desireable to trade with opponent's removal spells.