There are two triads one is the Light triad which includes Nature, The Burning Legion, and the Naaru. Within that triad Nature is in conflict with the Burning Legion. Fel is the opposite of Life and it's Fel that drains life. Nature is in the white pillar of Order and The Burning Legion is in the Black pillar of Disorder. In duality of the first triad there is Void which includes The Titans being in the Pillar of Order and Death being in the pillar of Disorder, the Old Gods being in conflict with the Narru. within the tree there are individual triads of elements that are in harmony, such as Decay, Fire, Water and on the other side, with Earth, Air, Spirit. All the Primal Elements to form our Material Universe in the center with the Emerald Dream being on the side of Order and the Shadowlands being it's opposite on the side of Disorder. In Azeorth's creation it's said that unlike all other Titans she did not have a balance between all of these primal elements, she absorbed more Spirit, giving more weight to Life and the Emerald Dream and that could explain the power imbalance leaning towards Order and could explain why the factions in the Shadowlands have to fight for spirit resources or why Azeroth is a 'prison.' Blizzards version of their cosmology chart is not a perfect example of a Tree of Life but there is enough to create one out of what they have provided.