The Dangers of Nibel are hazardous entities of the forest that can damage or even vanquish Ori if contact is made. Some dangers can be found all over the blind forest (such as spikes), while others are native only to certain areas (like Lava). But, indigenous or not, each danger exists for a sole purpose: to harm Ori.

Thorns are ubiquitous and probably one of the most common threats of the blind forest. They can be found at the bottom of pits, hidden inconspicuously among patches of grass, or growing on the sides of walls. Usually they are used to increase an activity's difficulty, as they are very easy to run or jump into. There are some thorns, however, that can be destroyed by Sein's light; these will glow a toxic purple or magenta. Permanent thorns are mostly either orange or brown, and are unaffected by attacks.
Spikes are much like thorns, except oftentimes they deal more damage (some can even cause Instant death).

Ori looming over unclean water, before entering the Ginso Tree


Ori surrounded by clean water, right after leaving the Ginso Tree

Water is a partial hazard, as doesn't always harm Ori. At the start of the game, all water is harmful, and Ori will lose one health per second if they touch it. It has a purple hue, indicating the danger.

After restoring the Ginso Tree, the water in all of Nibel has been cleansed, and it turns clear. As a result, it does not instantly harm Ori. Rather, Ori will slowly lose air when submerged. When the air meter is empty, Ori's health will drop by one at around one per second, eventually resulting in a death. The air meter is brought to max immediately when Ori is above the surface, however any health lost does not regenerate. If the player has unlocked the "Water Breath" ability, then Ori's air meter will not drop, and no health will be lost.

There is also a place where Ori does not swim, even after clearing waters, just before the entrance to Mount Horu. The water is yellow and bubbling, and Ori dies instantly if he touches it.

Lava is an environmental hazard. It is only found in and around Mount Horu. Lava causes an Instant death to Ori. As Ori travels through Horu, the lava is slowly cleared out, allowing access to the final sequence.
Rotating spikes

Rotating spikes in Spirit Caverns

Rotating spikes are mace-like contraptions that rotate either clockwise or counter-clockwise. As they rotate, they leave a trail of purple hue. They hinder Ori's progress while moving a boulder and deal damage when in contact. They are only found in the Spirit Caverns and Hollow Grove.
Super-Heated Surface
There are two forms of super-heated surfaces. The first is found in Horu Fields. This kind causes Instant death to Ori. This hazard is static, eaning it cannot be destroyed or moved. The second form is found in Mount Horu itself. This form heats up" when Ori stands on it, and will harm Ori one point of health for every second.
Ice breaths

Dangerous light breaths during the Forlorn Ruins escape

Main article: Enemies of Nibel
Main article: Kuro