We want to improve the survivability of the minions, so we will first choose the cards that can give health to other minions.
Here are the options:
Minion:

Spirit Vessel: When killed, its spirit flies to a random friendly Minion and gives it 100 extra health.


Priestess: She will constantly heal a nearby damaged friendly Minion.


Spiritmancer: Rips the spirit from dying enemies it's attacking. The spirit flies to a random friendly Minion, giving it 100 extra health.

Spell:

Healing Fireball: Heals all friendly minions by 400.

Spirit Infusion: Summons 3 Spirits over 9 seconds. Each Spirit flies to a random friendly Minion giving it 100 extra health

Building:

Healing Shrine: Heals all nearby friendly minions over time.

In my opinion, Minion > spell (obviously, you do not want Xiao Long to go crazy when it singlehandedly kill a 5+ mana minion), also use the wild cards option.

Fire Ball is chosen to counter horde minion card (works well on Blood Imps, if they dare to bring that card to 2v2), Ghost, Snake Druid, etc.

Ghost (Legendary card) is chosen to counter high mana melee minion, or Lightning Bolt (Regular card, works best when there is only one high mana enemy minion on the field, weak against Ratbo master, because its perk skills)

We are still missing a minion that can deal massive damage to enemy tower, you can choose whatever you want, I prefer Blue Golem because it cost 7 mana and attack both minion and building. The card works best with Priestess or Spiritmancer. So wait when you got full mana and summon them together.

We now got 2 spots left. This deck is weak against flying minion, so the rest of the 2 cards should go to minions that can attack flying target.

Now the deck is complete:


As for the master, I use Mordar (nothing is better than the 0-mana cost wall - Tombstone, and it can also ressurects the next friendly minion that dies) or Apep (all the perks are good).

Now you are good to go. Be a bulldozer and wreck your way to victory.

PS: This is not never-lose-a-single-match deck. There will be decks that counter this one. RNG sometimes also play an important role in match. Test the deck and modify it if needed be.

Branding image source: https://i.ytimg.com/vi/F7Gq5EZKbVg/maxresdefault.jpg