If I didn't post it in the thread that gave you this idea, the deck below is a fantastic multiplayer life-gain deck.
As is, it's extremely aggro and can gain absurd amounts of life; I've been up over 100 on a few occasions. Having 4x Ajani's Pridemate is critical as is having 12x cards that gain you life when creatures ETB (Soul Warden, Soul's Attendant, Suture Priest). In your case, since you're running green, you could use Essence Warden instead but I strongly recommend dropping green altogether and playing the build I have linked above. As mono-white you are now open to Honor of the Pure/Crusade which turns the little guys that were just gaining you life into effective beaters.
Serra Ascendants and Squadron Hawks are also very important to the deck. They provide the kill in most games.
Lastly, I do not like the Inquisitor Exarchs in my build and will be dropping them for Chalice of Life. Everything else in the deck runs very well and it's very fun to play. It lacks true control and flying defense but the absurd amount of life gain in the deck usually makes up for it. Especially in a large, multi-player game where you have so many people triggering the Soul Wardens and her sisters.