The Other Self

Many wizards and other medical practitioners of the mind have theorized that people hide their true selves behind a mask. The mask is the persona you create of your best self. The self you want others to like, the self of the public. Where do these masks come from and where do our true selves hide? The Sea of Shared Consciousness. You've come in contact with this mysterious plane of existence. A traumatic emotional event or a driving curiosity lead you to your patron, a shadow of yourself. It only wants what you want, as long as you have the strength to withstand adversity. You've made peace with your other self and have been granted power from the sea of shared consciousness. Your other self can do many things for you and its interaction with the material plane is what drives most of your abilities. 

Pact of the Mask

If you "accept the mask," this feature replaces the standard warlock pact boons. You can only use the mask with other pact boons at the DM's discretion. Accepting the Mask allows you to use a free action to summon the mask on your person, much like a pact weapon.

While you don the mask, you may maintain concentration on up to two spells. If you try to cast a third concentration spell, the first concentration spell is dropped. All normal rules for the spells apply, such as duration, time to cast, and any consumed materials. If you lose concentration, you lose both spells

Accept the mask

Your other self presents a mask to you, It can take any shape or form you desire as long as it fits somewhere on your person. The mask is the strongest connection your other self posses to the material world. As long as you have the mask, your Shadow can channel it's greatest powers through it. The mask can never be forcefully taken from you. While you don it, it is impossible to remove by anyone other than yourself.

Gain proficiency with one tool or skill and gain the ability to concentrate on up to two spells while you don the mask. Your shadow combines its knowledge with yours and together you can do great things. 

Reject the Mask

Perhaps you're not ready for this power yet. Or perhaps the idea of dawning a new mask after casting off your old one doesn't feel right to you. Or perhaps you just want some of the classic relics patrons tend to bestow on their loyal subjects. Choosing this option allows you to use standard pact boons as normal.

I am You

At 6th level, your Shadow takes on some of the mental burdens of spellcasting.

If you Accepted the Mask, gain advantage on concentration checks to maintain a spell. If concentration is lost, only lose one spell. Also, gain an extra attack per action like the Extra Attack feat.

If you Rejected the Mask, you gain advantage on concentration checks for spells. You may only concentrate on one spell. 

You are Me

At 10th level, if you Accepted the Mask, you can use a Bonus Action to cast a spell even if you used an Action to cast a spell.

We Are One

At 14th level, if you Accepted the Mask, your Shadow can physically manifest itself near you for 1 minute. Your Shadow's initiative is the same as yours and it acts on your turn. It must remain within 10 ft of you. Your shadow has all your stats, spells, actions and feats, including the "I am You" and "You are Me" features. Your shadow is considered an allied creature that follows your directions explicitly. You and your shadow can benefit from all ally actions and maneuvers such as Flanking. Your shadow disappears after it's HP reaches 0 or the duration of the summon ends. 

If you Rejected the Mask, you can impose advantage on your attacks and disadvantage on your enemies attacks against you for 1 minute.