Fracturing

You close your eyes, stare at object or into space, whichever lets you focus more, and you breath. In, out. In, out. 

Slowly, you becomes you both.

(StolenInspired by This Cruel Design) Fracturing allows you to split your consciousness in two, allowing you to focus on two different task simultaneously without issue, as if there were two of you inside your brain. 

When done under ideal circumstances, you calmly take a minute, and the the fracture happens without issue. However, under not-so-ideal circumstances, say a battle, things can get dangerous when fracturing(and un-fracturing) are done too quickly. 

(Adjust these numbers as necessary, I'm in no way claiming that these are good, they're just numbers I chose) When you feel that it is important, you can choose to rush the fracture. Roll a CON DC 10 Saving Throw. On a succeed, if you were 3 or lower from succeeding you have disadvantage to checks and saves for 1 round, otherwise you push past the adverse effects of the rushed fracture. On a failed save, you are unable to fracture and have disadvantage on checks and saves for 2 rounds; rolling 5-9 you take 2 psychic damage, 2-4 you take 5 psychic damage, and on a 1 or below you effectively have a stroke and pass out, talking 7 psychic damage and falling unconscious for 1d4 minutes, able to be jolted awake by a party member waking you after 2 rounds(as in if you fall unconscious, you are unable to be awoken for 2 rounds, at which point a party member's attempts to wake you will work, otherwise however long you rolled). 

This same thing happens when you rush to un-fracture. You may also fracture again, allowing 4 consciousnesses, but basically everything doubles. You could also go again but the effects when rushed are so drastic, that you can only remain conscious for so long before stroking(passing out) and taking 2d8 of psychic damage + 7. You must make a CON saving throw every round, at disadvantage, -3 in order to remain conscious. (With the cinematic option for the DM to allow you to carry out a certain task driven by willpower before falling)

You're able to calmly fracture up to three times, allowing 8 consciousnesses, it taking double the time each time(1 min, 2 min, 4min). And yes, that means you can have multiple concentration spells at once, you rolling each save separately when something interrupts your concentration. If multiple spells require an action or bonus action to redirect and you are fractured and concentrating on them, you may use that 1 action or bonus action to redirect however many you choose and are concentrated on. When there are multiple enemies surrounding you while you are fractured and unconcentrated on other things, you may avoid disadvantage from being flanked(if that's how flanking works-). Fracturing opens a lot of possibilities, and it is up to the DM what flies and what doesn't. 

Also, a story element, when you fracture, it is often times exhilarating and when you un-fracture, it's almost disappointing going back to thinking one-dimensionally.