I wouldnt recommend playing Tithe in any deck playing green, as it doesnt put any lands youre searching for into play, but ensuring you can start with 2-3 lands and an extra color or 2 of mana earns it a slot in many decks
Upgrades Some of the upgrades are cards I already mentioned: Thassas Oracle adds an easy and constant way to win, Shuko, while I think overpriced at the moment, is still solid to add, and Senseis Divining Top lets you set the top of your library.
Notably, because walls and birds are worst at blocking large creatures and Wingmantle costs white mana anyway, Destroy Evil is often going to be the best common removal spell, killing big creatures and being one of the best destroy enchantment cards in white
Here, Grzegorz Rutkowski's updated art showcases Garruk's sinister transformation and the toll it takes on his sanity