This is "Heal the Cat!" otherwise called, "Get a Life!" -- a mono-white voltron deck based on lifegain, counters, and equipment -- all with a fuzzy feline at the helm. What more can you ask for?
The goal is to get a as many repeatable lifegain triggers operating as possible to put counters on the commander, Ajani's Pridemate, throw down as much equipment as the kitty can carry, then swing for commander damage victory in a matter of turns. The life-increasing cards are split into "life gain" which are repeatable and "life plus" which are one-offs -- mostly removal, card draw, and entrance effects. Most of the equipment buffs power and toughness, but some give evasion keywords.
For repeatable lifegain, Ajani's Mantra is a powerhouse, alongside its removal cousin Recumbent Bliss. Sisters Soul Warden and Soul's Attendant both make an appearance, as does their estranged wine-aunt Suture Priest. Their flamboyant uncle Leonin Elder does the same with artifacts, and his lifelong roommate Pride Guardian gains life whenever he blocks. Student of Ojutai is too busy studying to join the family reunion, but he does send letters. At the kids' table are Silent Attendant, Shu Farmer, and Soulmender, which gain a life on a tap ability. Also present are Marble Chalice -- the same effect on an artifact -- and Pristine Talisman, which gives you a generic mana to spend alongside the lifegain trigger. All of these cards are the main focus of the deck's synergy with Ajani's Pridemate -- it doesn't matter how much life we gain, but how often we gain that life. Topping off this family tree is granny Soul Shepherd who kicks everyone out of the house after dinner. Reaping the Rewards does the same with all the extra lands that this low-curve deck will eventually collect, and it can make a great surprise finisher if you sacrifice all your lands before damage is dealt.
The main one-off life triggers are the meek sources of white card draw. Renewed Faith, Revitalize, and Survival Cache all essentially read "put a counter on Pridemate, draw a better card." Inspiring Overseer and Priest of Ancient Lore do the same and also provide a blocker. Most of the targeted removal in this list gives a trigger as well. Kabira Crossroads and Radiant Fountain give some life when they enter, and the Streets of New Capenna lands are better Evolving Wilds and Terramorphic Expanse for this deck. While we're talking about lands, it's worth noting that Opal Palace can give a head start on recovery if Pridemate has been bolted, burned, or battered off the field.
As far as equipment, there are only a few of special note. Armory of Iroas and Greatsword of Tyr both pile more counters onto our feline leader, and the latter can keep a blocker out of the way as well. Blight Sickle deals damage via irony and leaves enemy creatures with -1/-1 counters, and Explorer's Scope gives a soft-scrying and deck-thinning effect with each swing. There's a few that add flying, but Vorrac Battlehorns and Whispersilk Cloak are the real evasive powerhouses. The rest just add power and toughness so commander damage isn't entirely dependent on how much life has been gained since Pridemate was last cast. As a side note -- I've added custom converted mana costs to all of the equipment to include their equip costs as well. This makes the deck seem higher curve than it is, but it emphasizes getting the gear on the gato quickly. The deck could probably even afford lose a couple basic lands, as I find it tends to flood somewhat often.
The short selection of flying lifelink creatures can pick away at enemies' life totals and give extra counters to our main mouser. Sky Crier also has some great diplomacy potential. The sideboard has alternative, higher-toughness lifelink creatures for defending against aggressive token decks, or if your opponents have solid answers to the smaller flyers. Basri's Acolyte has the nice bonus of giving Pridemate an extra counter when it enters. With all the equipment in this deck, it's definitely feasible to keep any combination of them durable while still giving most of the weapons to the commander.
There's fair list of protection spells to keep the kitty (and the counters) on the battlefield for as long as possible, and they can double as evasion to land killing blows. Apostle's Blessing and Feat of Resistance synergize especially well by paying life and adding a counter respectively. Probably my favorite card in the deck, Test of Faith is full of flavor, and it's won me games before. Dawn Charm and Death Ward both offer the alternative of regeneration, and Mana Tithe totally throws enemy expectations of a white deck.
On the maybe board are cards which just don't quite make the cut. Ephara's Radiance and Oreskos Sun Guide is a fun combo, but getting them together is a fragile and mana-intensive challenge. Loyal Sentry is a solid diplomatic threat, but tokens can become a huge threat in this format, so Holy Light gets the last removal slot. The acquire list currently has cards which tap to add life that I might pick up soon. I'm a little hesitant on Luxa River Shrine because of the mana investment needed, and the payoff isn't very meaningful in this deck. Pious Kitsune functions exactly the same as the others just with extra wording, and Traveling Minister provides a temporary point of power to Pridemate alongside the counter. I'll probably cut Vulshok Morningstar, Blight Sickle, and most unfortunately Sacred Cat if I do get them.
This deck definitely has its weaknesses -- tokens and smaller creatures can overwhelm it, well-timed removal can wipe turns of progress on +1/+1 counters, and counterspells can righteously ruin a game plan or a specific play. However, the constant life gain makes it stand up well to attrition and burn decks, and the low cost of Ajani's Pridemate makes it easy to recast, re-equip, and get back to swinging. With how quickly the primary puss can ramp up its power, sixteen commander damage is an easily realistic goal no matter the stage of the game.
Anyway, you get the picture... now get a life!
