The Most Random Changes to Keys I came up with.

Keys:
All Keys allows you to use the Channelling Action to unlock the potential of reading the Aura's of the Hatch when it's closed and Chests within 24 Meters.
When the Key is out of Charges, you can NOT instantly unlock chests or unlock Hatch with it.

Common (Broken Key): You can NOT unlock Hatch or instantly unlock chests by any means.
Channelling will read Auras within 24 Meters.
10 Seconds of use.

Uncommon: Channelling will read Auras within 32 Meters.
15 Seconds of use.

Rare: Channelling will read Auras within 32 Meters.
20 Seconds of use.

Very Rare: Channelling will read Auras within 40 Meters, and you can see the Auras of Exit Gates.
25 Seconds of use.

Ultra Rare: You are Given 2 Keys at once.
Channelling will read Auras within 48 Meters, and you can see the Auras of Exit Gates and Generators.
Channelling will only use up 1 Key at a time.
Using up both Charges of the Keys will completely deplete them.
Using the Drop Action, you will drop both Keys at the same time, but you can pick up only one of them.
Any Addons you run with this Key will be linked to both Keys.
30 Seconds of use.
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Key Addons:

Common: Increases 15 seconds of use with this key.

Common: Increases Aura Reading Range by 8 Meters.

Common: Reduces the time to unlock the Hatch by 1.5 Seconds.

Common: Picking up another Item will allow you to still hold on to the Key.

Common: Once you have been Sacrificed, you do NOT lose your key, lose this addon instead.

Common: Channelling this Key will reveal all Survivor's Aura to you and your Aura will be revealed to all other Survivor's within 24 Meters.

Uncommon: Once your key is out of charges, any Keys, chests containing keys, and Survivors holding a key will have their aura revealed to you within 24 meters.

Uncommon: Once your key is out of charges, you keep the effects from it for another 20 seconds.

Uncommon: This addon completely repairs the Broken Key, the Broken Key can now unlock the hatch and have the effect from the other addon you add to it.

Uncommon: Press the Secondary Action while holding this Key.
This Addon will allow you to place the Key you are currently holding in your pocket.
While the Key is in your pocket, you can NOT use any effects from the Key, the Killer can't see you have a Key, and you can NOT drop the Key or the Key can NOT get dropped out of your hands by the killer.
Pushing the Secondary Action again will allow you to pull the Key out of your pocket.

Uncommon: If your Key has any charges left, unlocking the Hatch, a Chest, or Safe will replenish all of it's Charges.

Rare: Press the Secondary Action While Holding Channelling this Key.
You will drop the Key and 15 Seconds after you drop the Key:
-It will create a loud noise notification for the Killer.
-Survivor's can see the Aura of the Key once it has been placed down within a 16 Meter Range.
-Once the Killer is within 16 Meters of the Key, the Killer will have their Aura revealed to all Survivor's until he leaves the range.

Rare: While Channelling, your movement speed is increased by 10%.

Rare: Channelling this Key, you can determine the progression of Generators by the Intensity of their Auras within 48 Meters.

Rare: Giving your Key to another Survivor will replenish the Key's Charges by 100%.
This effect only works one time.

Very Rare: You can Instantly Unlock Chests with this Addon.
Using this Addon will deplete your Key and any of it's Addons instantly.
This does NOT work with the Broken Key.

Very Rare: Channelling this Key will reveal the Killer's Aura when outside of their Terror Radius.

Very Rare: Once you unlock the Hatch, a Chest, or a Safe, the Key remains in your hands.

Ultra Rare: A Locked Safe will spawn on the map.
Unlocking this safe will contain 2 different Ultra Rare Items with 1 Ultra Rare Addon.
The Safe will be revealed to all Survivors with a White Aura except for you within 16 meters.
Unlocking this Safe with your key will deplete the Key along with it's Addons.
Key's will NOT spawn inside of Safes.

Ultra Rare: Once the Hatch spawns, 2 Hatches will spawn instead.
If the map has a Killer Shack, Main Building, or both, both Hatches has a 100% Chance of spawning in both.

Super Rare: You start off the Trial with 0 Charges in your Key.
Escaping through the hatch with this Key will grant you 100% Bonus Bloodpoints in the Survival Category.