This subclass was based around time and themes from order like clockwork soul. Comments and concerns are welcome I think it might be a tad too powerful and front loaded  The wording might be a bit clunky as well sorry about that not too great a writing clear rules 

A timeless force that governs causality and balance. Whether a divine judge, a sentient paradox, or a cosmic algorithm, your patron grants you power to redistribute harm and manipulate time itself — not for chaos, but for perfect equilibrium.

You intercept harm and store it for future use.

• Chronal Buffer: When a creature within 30 feet takes damage, you can use your reaction to reduce the damage by 1d10 + your Warlock level + your Charisma modifier. You can use this feature a number of times equal to your Charisma modifier per long rest.

• Temporal Reservoir: When you reduce damage with Chronal Buffer, you may store the amount reduced as a Chronal Charge. You can hold up to a number of charges equal to your Charisma modifier. Charges fade after a long rest.

You can redirect stored damage into attacks or spells.

• Expend Charges: You may expend Chronal Charges in two ways:

  • Reinforce Shielding: Spend 3 charges to use Chronal Buffer again, even if you've used all your reactions for the day.

  • Echo Strike: When you hit with an attack or deal damage with a spell, you may expend 1 Chronal Chargeto deal bonus damage equal to your Warlock level + your Charisma modifier. This damage bypasses temporary hit points. You may only apply one charge per target per turn.

Level 6: Temporal Equilibrium

You manipulate outcomes to restore balance.

• Chronal Reversal: When a creature within 30 feet makes an attack roll or saving throw, you can use your reaction to force them to reroll it. You must choose to use this feature before knowing the result of the reroll. You can use this feature once per rest.

You fracture time to act in multiple moments.

• Split Second: When you cast a spell, you may use a bonus action to delay its effect by 1 round. The spell still consumes your action on the current turn, but its effects activate at the start of your next turn. This allows you to cast a second spell normally on the next turn. You can use this feature once per rest

Your mastery of temporal balance deepens.

• Double Reversal: You may now use Chronal Reversal up to twice per long rest.

Is this 2014 rules? 2024 Warlocks don't get their subclass until level 3, just making sure.

A few notes:

Chronal Buffer: You shouldn't include the Charisma Bonus in the damage reduction. Also, as a general rule, the protective/reaction abilities are 6th-level, but I see that it's fueling other abilities. Also, and more importantly, this is it? Your first ability for the class is a minor damage reduction reaction? And you've built a LOT of the rest of the class around this? Let's press on...

Temporal Reservoir: I see what you're doing here, but there's no benefit to having a temporal reservoir until level six. Throw a bonus of some sort in here. You gain a +1 to something for each charge, maybe? AC? Saving Throws? I don't know. Also, if the triggering effect is Chronal Buffer, and the max we can have is our Charisma modifier in charges, we're going to run into a problem very soon.

Expend Charges: And this is where we're going to get into trouble. First off, a standard array player is going to get three charges - MAYBE four - by the time they get this ability, and five max at any given time. That means that "reinforce shielding" is gonna cost MOST of your daily resources - assuming you can even accrue them - in one burst. Also, the second ability (which should augment damage by ONLY your level OR your Charisma, not both) is... I dunno, fine, I guess. Not terribly exciting.

Chronal Reversal: A little bleh. Also, I'd say you can recharge it by spending a Pact Magic slot. I dunno, I don't hate it, but it's not much of an ability for a whole subclass level.

Split Second: I don't know 100% what this achieves. I guess being able to get two spells off in one round is interesting, but it's not actually any more powerful than casting two spells on two turns unless you're doing some pretty heavy battlefield manipulation in-between turns.

Double Reversal: You have made the capstone ability the ability to do the least interesting thing more than once. Fiendlocks are sending their enemies somersaulting through Acheron, and you're forcing a reroll on a saving throw an additional time.

I think there's some good ideas here, and I think there's a little cruft, I think, with some reshuffling, and a little innovation, you can make this really neat.

Level 3: I'd give two abilities. I'd give a spell list of always-prepared spells (Misty Step, Haste and Vortex Warp feel like must-haves), and I'd give Chronal Reversal, but I'd change the uses to "a number of times per Long Rest equal to your Charisma modifier (minimum 1)" and I'd consider adding "you may recharge your uses of this ability by spending a Pact Magic slot (no action required)."

Level 6: This is where I'd add Chronal Buffer and Echo Strike, but I'd make them feed off each other. Something like:
   Temporal Shielding: You warp the fabric of space and time to delay an attack, providing equal parts offense and defense. After taking damage, you may spend a reaction to reduce the incoming damage by 1d10 plus your Charisma Modifier (minimum 1). On your next turn, you may release the stored up energy, increasing the damage of your next spell or attack by your Charisma Modifier (minimum 1). You may use this ability [insert amount of times you want this to be able to go off] times.

Level 10: I'd change Split Second into something more like a Haste-enhancing ability. Something like, "You may cast Haste once per Long Rest without expending a Pact Magic slot, and when you cast it in this way you do not need to maintain concentration on the spell." 

Level 14: I'd implement some battlefield control. Maybe create an effect like the Scatter spell, where you can move people around the battlefield. Instead of picking five creatures, you could affect a 20-foot radius sphere or something. Be a fun way to create some havoc in a way that also feels wibbly-wobbly timey-wimey.

Thanks for the detailed explanation. We are playing 14 rules just to clarify. I wanted to build this around as a tankier warlock. The first level features I liked as the idea of reducing damage and then then sending the force absorbed by time back. Basically abusing your patrons power. The thing about storing charges is so that I can use them later e.g during a boss fight and I know the 6th and 10th level features aren’t great I was trying to make up for some pretty powerful 1stlevel features(or so I thought they were). I’m making adjustments based on your feedback will post a finished form in a couple of days

completely forgot about extra spells have you got any more idea(sorry I’m just always bad at the spells part) :/

When it comes to extra spells, look into ones that feel time-and-space related. I think teleportation-style spells are always good, but you don't want to have the entire spell list be Misty Step and Dimension Door. I'd work in a couple damaging spells and the like. Worth noting that, unlike 2024 subclasses, that grant the spells in the subclass spell list as "known" spells, the 2014 Warlock subclasses usually just add them to your list of "knowable" spells. So you'll want to look outside of traditional Warlock spells.

I see your vision with the charges. My criticism is that it largely creates a lot of complexity and tracking for the player, in exchange for a mixed bag of returns. If you want it to be a thing, make it the thing, and build the rest of the class around it. At first level, you can absorb attacks, store charges, and use the stored charges to augment damage. At sixth level, you can use stored charges to reroll saving throws and attack rolls. At tenth level, you can spend charges to create a haste-like effect, and at 14, you can spend all your charges to do something really dramatic. Maybe somewhere in there, you add an ability where you start combat with one charge if you don't already have one or something like that.

Great ideas about using charges for everything. How about at 14 you have double the amount of charges maximum and regain half on a short rest?