Spell Stealer

Your magic comes from the perverted amalgamation of others powers meshed with your own. You may have formed an incongruous bond of magic and blood by compressing arcane energy forcefully into your body, resulting in an artificial sorcerer whose magic is as interchangeable as a cog in a machine. Perhaps you are an instrument of a god, used to balance the playing field in a part of the world where magic runs rampant. Or perhaps you were simply born with this innate ability to rip the magic from the hands of whoever you desire. However the magic came to be in you, you possess the remarkable aptitude to mimic others magic. It's up to you if you choose to assist or violate those who have attained their magical abilities.

Hijack

Beginning at 1st level, you can use your action to make a ranged spell attack that produces an arcane tether and extend it towards a spellcaster you can see within 60 feet. The tether is visibly bright, makes a loud sound for the duration but is intangible. Once tethered, select a spell of 3rd level or lower that you know the target knows and has prepared and expend sorcery points equal to the level of the spell chosen (or zero points if the spell is a cantrip). Your arcane tether writhes violently, singling out the chosen spell in the caster's mind before hurtling back and bestowing a copy of the spell for you. Add the chosen spell to your spell list; if it is not on the sorcerer spell list, it counts as a sorcerer spell for you. The spell remains on your spell list until you use this feature again. It does not count towards your number of sorcerer spells known.

Quell

When you reach 6th level in this class, you learn counterspell, which doesn't count against your number of sorcerer spells known. If you successfully use counterspell to counter a spell you can expend a number of sorcery points equal to half the level of the countered spell to temporarily add it to your spell list, treating it as a sorcerer spell when you cast it.  Casting the Quelled spell removes it from your spell list.

Seizing Surge

Starting at 6th level, when you Hijack or Quell a spell, you can make your arcane tether become tactile. The target of your attempt makes a Wisdom saving throw against your spell save DC. On a failed save, the target suffers force damage equal to your sorcerer level + your Charisma modifier and is pulled up to 10 feet towards you. On a successful save nothing happens, though you take the spell as normal.

Improved Hijack

Starting at 14th level, the range of your tether doubles to 120 feet when you use your Hijack ability. Additionally, you can now take spells up to 6th level When taking a spell of 3rd level or lower, your spell attack on Hijack has advantage

Arcane Redistribution

At 18th level, when you successfully Quell a spell of 6th level or lower, you can instead choose to destroy the stolen spell, converting its energy into a number of sorcery points equal to the level of the spell quelled.