Chronomancer

Time mages: practitioners of a meta-school of magic of such potential for havoc that its very existence might be one of the most fiercely-guarded secrets even from some of the most learned grandmasters of magic.  Chronomancy - the power of Time itself.  Chronomancers are most typically taught this secret power by other Chronomancers, often who have been watching the candidate in secret, at multiple points in their life, and frequently from another time period than the candidate; most typical, but still extremely rare.  Even more unlikely, sometimes a Chronomancer learns this secret art by stumbling upon some text or scroll that contains knowledge of the demiplane of time, or advanced magical theory on manipulating temporal flow while also containing the paradoxical repercussions of such meddling.  Most rare of all, though it happens, a studying wizard might come to hypothesize - correctly - about the nature of time all on their own.

Depending on the setting, Chronomancy may be a profoundly secret art, or it may be a commonplace field of study.  Given the delicate nature of their art, Chronomancers might strongly tend to guard the secret of their power and their study above all else.  If it is a secret, then should this secret be let slip too publicly, or too frequently, the offending Chronomancer may find that they have a host of other Chronomancers to contend with; or worse: the native creatures of the demiplane of time.  An adventuring Chronomancer may choose to divulge their own nature to close, trusted companions, or even mentor and train a spellcasting companion in the ways of Chronomancy, but in realities where Chronomancy is unspoken of (DM discretion), the Chronomancer should avoid selling, trading, or carelessly discarding Chronomantic spells or literature.  In settings where Chronomancy is secret, Chronomancers often masquerade as Transmuters, Diviners, or a "peculiar student of magics that fall somewhere in between the two".

A Chronomancer may be an eager historian, travelling back and forward through time to record events of history with unmatched accuracy; or may be an opportunist, jumping to points in time when things are (or will be) known to have gone mysteriously missing... only to return home to fame or profit; or could be an idealist who leaps through time, righting wrongs, restoring timelines to "what they ought to be", or attempting to alter events to suit their own personal ideal history of a family, city, or realm - though often things work out in a way unexpected by the meddler.

In all cases, Chronomancers understand the dangers of recklessly meddling with the histories of reality, at best trying to repair or prevent damage to the fabric of reality whenever they see problems, and at least attempting to avoid getting caught up in any untempered temporal paradoxes personally.  Even those who manipulate time for selfish gain or personal ideology understand that there are some laws of nature that should not be carelessly ignored.

Foresight

 Beginning when you choose this school at level 2, your studies allow you to briefly glimpse pieces of the immediate future. You can not be surprised in combat and you use your Intelligence modifier instead of Dexterity when determining Initiative.

Alternate Reality

Beginning when this subclass is selected at 2nd level, the Chronomancer learns how to create small variations in the probabilities of reality. Each variation lasts only a moment, but creates alternate results for one recently-past event. When altered in this way, any one event attempted by a target the Chronomancer could see is recalculated, essentially allowing (or forcing) that character or creature to make a new die (or dice) roll. Only events that begin and end in a single round can be affected in this way. Only one roll-event can be rerolled. You may use this ability a number of times equal to your INT modifier per long rest.

Quantum Leap

At 6th level you gain the ability to displace yourself from time by a few moments. When a creature attacks you or makes an attack with an area of effect that you are included in, you may use your reaction to blink into the future and take no damage or effects of the attack. You may reappear, at the beginning of your next turn in a space up to 30 ft from your original position. If a creature has occupied your space in the time between your disappearance and reappearance, you take 1d10 force damage and are shunted to the nearest occupiable space. You can use this feature after the creature has announced intent to attack, but it must be used before the creature rolls to hit or you roll your saving throw. You can use this ability a number of time equal to your proficiency modifier per long rest.

Timeslip

Starting at 10th level, your studies into the power of time have left you with several benefits to your passive lifestyle, as well as several quirks from interacting with the raw force of time. Casting a spell as a ritual adds 5 minutes to the casting time instead of 10. You can gain the benefits of a long rest, a short rest, and attunement in half the time that is usually required.

Timeslip

At 10th level, you gain the power and knowledge to send spells backwards through time. Your future self is capable of using you as a temporal anchor: a specific, isolated more within time around which spells can be created.

Gifts From The Future: As a free action, you may have a spell arrive from the future with no discernible source. This may occur on another creature's turn, as though an unseen caster had readied an action. Choose a spell you can cast with casting time of one action or bonus action from the wizard spell list. The effects of the spell occur with no action or component cost required, although you count as the caster of the spell for purposes of range, concentration, and ability scores.

Temporal Balance:  Every effect requires a cause. When a spell arrives from the future, the temporal scales become unbalanced. After using the Gifts From the Future feature, you acquire a temporal debt: a promise that a spell will be cast backwards to rebalance the scales. While you have a temporal debt, you are unable to use the Gifts From the Future ability.

Repaying a Debt:  During a short or long rest, you can perform an hour-long ritual to send the chosen spell into the past, thus paying off your debt. You may perform this ritual after a number of days equal to your wizard level , or before, you have used Gifts From The Future. At the end of the ritual you cast the spell as normal, consuming material components and a spell slot of the correct level. The effects of the spell don't occur at the time of casting. If you don't have the ability to cast the spell, you have to prepare, learn, or otherwise acquire the spell before you can perform this ritual. If you do not perform the ritual their are time based consequences that the DM is free to use

Time Heals all Wounds

You are now able to more easily affect others using your mastery of time manipulation, reversing time to the point where your allies wounds are no more. You may cast: Cure Wounds, Lesser Restoration,  Revivify, Mass Cure Wounds, Greater Restoration, Raise dead, and Regenerate using your spellcasting ability.  You may only use the ability if the affect you wish to cure or heal happens within 1 hour. You must've been present if you wish to cure or heal an affect if it happened more then 1 hour ago, up to a number of days equal to your Wizard level. (Healing done cannot be greater then the original amount of damage received, and the original spells restrictions take priority over this feature)