Time

Who and what is Time? No one knows. Even those who succeed in foraging a pact are unsure of what type of being they have contacted. A creature occupying the void on the outskirts of this plane? A being of the Far Realm beyond reality? Is it even one entity? Perhaps the patrons are a race of being that have transcended time? Or maybe Time is just a force of nature, as cold and impersonal as the stone it withers to sand? Whatever the case, one thing is for certain:

Time is an elusive mistress. She demands a lifetime of devotion before even the possibility of reciprocation. Most suitors die of old age, frustrated and spurned, after a life that, finally, amounted to nothing. But a portion of a portion do succeed, and to these few who have gained the attention of Time herself she gives a gift that is beautiful and terrible to behold. She weds them and marks them as hers for eternity.

Old Soul

You have spent a lifetime seeking a pact with Time. You are old and decrepit as a result. In order to choose this patron, you must be elderly--in the final 5% of your race's maximum lifespan. As a result of your extreme age, you permanently have three levels of exhaustion that cannot be removed by a long rest.

However, now that you have finally received the attention of Time, you slowly grow younger and healthier. Each time you increase your Warlock class level, reduce your exhaustion by 1. At the 4th level, all exhaustion from this feature is gone.

Expanded Spell List

Knowledge of certain arcane magic sometimes mysteriously materializes in your mind. It feels as if you have always known it. The following spells are added to the warlock spell list for you.

Flux

Starting at the first level, you can lightly bend the flow of time. Once per long rest, you may accelerate the time it takes you to cast a spell by a factor of 10, such that a spell that would normally take a minute to cast only takes 6 seconds. If you use this effect in combat, you may cast a spell that would take 1 minute or less to cast as an action on your turn. This effect works on ritual spell casting.

Time's Own

Starting at the Sixth level, you become immune to the effects of aging, having gained control of the flow of time within your own body. 

Additionally, when you take a long rest, you may change your age. This effect changes both your outward appearance, but also your mental and physical vitality. Choose 1 from infant, toddler, child, adolescent, young adult, adult, middle aged, elderly, or extremely old. You change to the chosen age from your current. Creatures who know you well but have not seen you at this age before must succeed on a DC15 perception check to recognize you. Creatures that do not know you well do not recognize you. 

If growing older, choose 1 from strength, dexterity, or constitution and 1 from wisdom, intelligence, or charisma. You may subtract up to three from the modifier of former to gain the same amount to the modifier of the latter. If growing younger, do the opposite. If your constitution modifier changes, recalculate your hit points (class hit die + level*constitution modifier).

Transient Ease

Starting at the tenth level, the durations you require for a long and short rest are reduced to 1 hour and 8 minutes, respectively.

Infinite Flexibility

Starting at the 14th level, in lieu of casting your arcanum spell, you can cast a different spell you know. The spell you cast instead counts as being cast with a spell slot equal to the spell level of the Arcanum spell it is replacing. Casting this spell still consumes your use of the arcanum spell.