Lifegain is the primary theme of this deck, and with a couple of combos going your way, you can very quickly take board control away from your opponent, and quickly lay a beatdown with massive creatures and trample. Scavenging Ooze comboing with Archangel of Thune was the original inspiration of the deck, with just one proc of Ooze giving you, 1 Life, +2/2 on the ooze, +1/1 on everything else.
The general idea of this deck is to quickly ramp into your midgame, where your cards are virtually unstoppable, and quickly establish board presence. From there, buffing your creatures to dodge most forms of red spells (Mizzium mortars comes to mind), and Trampling over your opponent with your infinite supply of life.
Anyway - The hand you'll want to keep will have at least one of each color of mana (a temple works nicely) in addition to one extra mana card and a ramper OR 3/4 land.
Let me iterate - DO NOT KEEP A HAND WITH ONLY WHITE MANA, as you have NO mono white cards for the early game, except in your sideboard. same goes for green, but at least you might be able to cast your Ooze.
To put early pressure on your opponent, come out swinging with a turn 2 Loxodon Smiter or Fleecemane Lion, depending if you ramped or not. Centaur healer works too, but is not ideal. Speaking of, don't be afraid to shock in your Gardens, as this deck has more than enough life to cover it. Follow up with a Turn 3 Unflinching Courage, and you'll quickly rack up a life advantage.
Keep your Charms until you ABSOLUTELY have to use them, they are your ONLY form of removal in this deck, but don't be afraid to use one to dodge a burn spell on your Lifelink creatures. You'll need them for the main event.
Trading creatures in this deck is fine, as the Scavenging Ooze + Archangel of Thune combo will do a ridiculous amount of work for you. pop it twice Turn 6 if you can after the Thune drop, and all of a sudden, you have 2 life, a 6/6 Ooze, a 5/6 Flying Lifelink Thune and +2/2 on anything else on your board at the time. Speaking of, you have no way of recovering your creatures from the graveyard, so feel free to exile them with Ooze, and keeping growing your unstoppable army.
Other combos come from Trostani, with her 3 mana Populate, populate anything and everything you can on your field, because you want her effect to be proccing as often as possible, which will in turn proc your Thune. If you don't have a Thune, using Trostani on Voice of Resurgance tokens is a great way to build board presence quickly, and sustain your life total.
If your opponent lets you get out of control, you'll find yourself with a ridiculous amount of Life, gigantic creatures that serve well both defensively and offensively, and trample so you can deal the finishing blow. Even the 1/1 Elvish Mystics in this deck can quickly get out of hand.
When dealing with other decks, this deck does great in the midgame, but keep an eye on your opponents mana, and large control spells like Cyclonic Rift, as there's little you can do to stop them. Pace yourself so when they do break out, you aren't devastated. Remember that Ooze can exile things OTHER than creatures too, so keep that in mind for flashback or other annoying cards that have graveyard presence. Lastly, if something, positively absolutely has to die NOW, then you CAN use an Unflinching Courage or your Charm to force a creature over the 5/X threshold, then exile it with a Charm, but this is very mana inefficent.
Some quick notes on other inclusions in this deck.
- Centaur Healer
This guy offers you a 3/3 for 3, which is on curve, but more importantly, gives you 3 life, as this will proc Thune, or if you have Trostani on the field, give you a total of 6 life. A great midgame card when you dont have your Smiter, but better held until you can combo it.
- Fleecemane Lion
Again, this guy offers some serious early to mid game power, 2 mana for a 3/3 will let you buff it on t3 for a 5/5, and making it monstrous t4 gives you a hexproof, indestructable, lifelink, trample 6/6. Good luck removing that.
- Advent of the Wurm
A 5/5 token for 4 mana at instant speed? Use it defesnively, offensively or just to proc Trostani, this card maximizes the value you get from your combo. Trostani essentially means you can cast one of these every turn, AND get 5 life out of it. Thragtusk eat your heart out.
- Garruk
A somewhat odd inclusion, as this deck primarily focuses on low to mid cost creatures, this guy is still great for thinning your deck once you hit that sweet 6 mana threshold, and will let you play lots of creatures. His high cost keeps him from being a 2 of, consider this one first as a sideboard option.
Lastly, your sideboard is intended to retool the deck into an Aggro deck, with pantheons, lashers and conclaves giving you more to do turns 1 and 2, while also offering some protection from control. Blind Obedience should be taken against Aggro (haste or Rakdos comes to mind), Rest in Peace against reanimator, Sundering Growths if you want more tokens and form of removal and lastly the Armada Wurm if you REALLY need another way to get a 5/5 Wurm token out.