[1] While setting off from Haldi's Oasis, the party senses several prevailing negative energies in the area. Necromantic energy in its pure essence flows through the area, and an overwhelming amount of chaos energy. Chaos in its pure form is necessary for creation of the universe, but tainted chaos contributes to formation of the void, the empty nothingness between planes.
[2] The greenery is starting to look too much like fall colors, as if they have not gotten enough sunlight nor moisture. Even though this area is as fertile as the surrounding lands, something in the air stunts is stunting growth. Thin spindly trees pepper the hills, significantly less leaves covering their branches. The usually fruitful berry bushes bear far less fruit. The area is still alive and vibrant, but the taint is far more amplified here. This energy likely originates from a major node of necromancy, such as a death knight, something that is truly against nature. The latent magic produced by such a presence is likely seeping into the environment itself, the land filtering out the that energy slowly but becoming damaged as a result, much like the blood vines in the Lenten Woods.