Planes Channeling

Sometimes through a magic item, an epic boon or any other strange circumstance, a non planes caller may gain the ability to channel the planes. However they gained the ability, it works as follows:

PLANESCHANNELING

Planescallers call upon their abilities by ascending to the different layers of the extradimensional planes known to them. Non planescallers which do so suffer an even more violent effect from these planes. This can manifest in different ways from augmenting their weapons, to unleashing pure elemental power, to simply making them lucky. Planescalling is a versatile and effective ability, but one that comes at great cost to the physical health of mortals.
LAYERS :
As a bonus action, you may ascend one or descend one layer a number of times equal to your proficiency bonus divided by 2 rounded down, in the plane you have access to.
Set aside a d4 to represent the current layer you are on for each plane, ranging from layer 1 to 4, if you are not channeling a certain plane, you do not need a d4 to represent that plane. You gain all the abilities of the current layers you are occupying and preceding layers.
Non Planescallers may only channel one plane at a time, even if they have access to multiple.
BACKLASH
When you start your turn while ascending you take 1d6 true damage for every layer you are channeling, for example if you are channeling 2 layers from your plane, you would take 2d6 true damage. If a planar ability references backlash, it means this true damage taken at the start of your turn. If you use a planes feature that mentions backlash without having taken backlash that turn substitute 2 in for every layer you are channeling.
PLANES
Whatever Feature grants you this ability will specify which of the "Planes" you gain access to. You may only channel layers of level equal to PB/2 rounded up. Many magic items which grant this ability may have other stipulations as to how you ascend or descend in planes, and may even have different rules on determining what layers you have access to or when.
SAVES
Should an ability or Spell granted by the Planescaller class require a saving throw, you calculate the DC by the following equation. Spell save DC = 8 + your proficiency bonus + your Constitution modifier