Warp sorcerer

You can channel your magic not through the weave or through an ancient ancestor, but instead through a dimension of danger and power: The warp. The warp is a realm of the long lost chaos gods that once roamed there, but their influence is there still. Those that use the warp to cast their spells do so at their own risk, since the warp isn't know for it's niceness regarding mortals attempting to use it's power.

The warp is open to anyone who knows how to try and use it. No matter your heritage, no matter your status, anyone can use it. All you need to use it properly is a guide to help you steer clear of the other citizens of the warp. And those without one? 

Let's just say the warp never lacks souls to power new sorcerers

Sorcerer of Chaos

You have stared into the warp, and the warp whispered some of it's secrets back at you

The chaos bolt spell deals an additional dice of damage whenever you cast it. You also learn this spell if you don't have it already

Overchannel

Channel the warp in order to hopefully turn a miss into a hit or a save into a fail. Such powers don't come without perils unfortunately.

Give yourself advantage on a spell attack roll on an enemy disadvantage on a saving throw against one of your spells when an attack rolls misses or an enemy succeeds a save on one of your spells. When you do you take (Sorcerer level)d6 psychic damage. This damage ignores resistances and immunities

Daemon ritual

Your sorcery using the warp has not gone unnoticed by the inhabitants of the warp. They are now here, willing to lend you their strength to reap chaos onto the material realm,

Summon a lesser Daemon to aid you or allow one to temporarily posses your body

Warp transit

You know the warp well enough to be able to navigate through it in order to teleport across long distances without being exposed to the many dangers inhabiting the warp.

Using a bonus action you can teleport up to 60 feet to an unoccupied space by opening a portal through the warp

Using an hour long ritual you can open a portal you can use to teleport anywhere you know the location of. You must have seen detailed enough pictures of where you are teleporting or you must have been there. If you don't have one of these things the ritual fails. The DM can then decide how long the trip through the warp takes and if there are any "Complications" (Daemon encounters) during the trip. You can take other people with you but they have to step through the portal out of their own will or they will phase through the portal.

Psyker supreme

You have seen a lot that the warp has to offer. More than most people would ever dare to dream about, and you are able to harness these secret for your benefit.

You are immune to being frightened and charmed after spending so much time researching the warp.

You can channel the warp to find any weak points in an enemies defense and how to exploit them. Using an action you can force an enemy to make a saving thow against your spell save DC. On a success nothing happens, but on a failure the number you need to roll for a critical hit against that enemy is reduced by one and their ac is reduced by 4.