The Collector

The Collector comes from an unknown realm outside of the current one. Being a researcher and a historian by nature, they are fascinated by the many new things to study. However, there are simply too many things for just one being to find them all. As such, The Collector forms pacts with willing mortals. The nature of this pact is that the mortals send the slain bodies of their foes to The Collector via an arcane ritual, in return The Collector grants powers and boons that will improve ones abilities.

Another Fine Addition to my Collection

Using an arcane ritual* that takes 1 minute you send the body or bodies of slain foes to your patron. In return, your patron will grant you knowledge of one of their resistances or weaknesses, if they have any.

If the body of the slain foe is not too badly damages or not damages at all, the DM may decide that your patron will grant you an additional reward of the DM's choosing.

* The way the ritual is conducted is open to interpretation and the player and/or DM can collaborate in order to make this work in your game.

Always More to Find

The Collector's fascination with every new thing they can find is unending. As such, they have made it so that their agents are resilient and able to endure much.

You are resistant to psychic damage.

Sleep and other mental effects such as those that apply the Charmed condition no longer have any effect on you.

Preliminary Results

After sending a specific amount* of bodies of the same creature to The Collector, he will have studied them extensively and reward you with some of the results.

You become proficient in a skill that is relevant to the associated creature.

You can only have one extra proficiency thanks to this feature, whether or not you can change it depends on your DM.

* The exact amount is decided by the DM

Seen this Move Before

The Collector has studied the creatures you have send him extensively and has given you insight into their movements. As such, you are able to recognize their attacks when they come at you and are able to avoid them more often.

You can impose disadvantage on any attack roll made against you by a creature that you have previously send to your patron.

You can use this feat as many times as your proficiency bonus and the uses reset upon a short or long rest.

The Final Results

After you have send a large amount of the same foe to The Collector, they have studied everything they can find about it and have successfully replicated it. However, in order to ensure that their replications act as they are supposed to, The Collector has decided to send a single specimen to you for you to test out in the field.

At the DM's discretion you may be granted a one-use summon of a creature that you have previously send multiple* bodies of to your patron. The creature uses its normal stats and has its normal actions. It takes its turn immediately after yours and lasts for 1 minute or until slain at which point it disappears and returns to your patron.

The summoning requires an action.

At the start of each of its turns, you must roll a D100. If you roll either a 1 or a 100 the summon goes wrong and explodes dealing 4d10 fire damage to everyone within a specific radius of the creature depending on its size or half as much upon a successful DC18 Dexterity Saving Throw.

Creature size - range of the explosion

Tiny - 5ft

Small - 10ft

Medium - 15ft

Large - 20ft

Huge - 30ft

Gargantuan - 60ft

* The specific amount is up to the DM's discretion but must be greater than the amount decided for "Preliminary Results"