Usurper

Your innate magic lacks the subtle traits that differentiates other arcane powers from one another. From this very absence in your magic, the ability to absorb the spells of others was born. Siphoning magic and adding it to your arsenal, and cutting the access your target has to it, though only temporarily.

Able to take the magics of others, will you turn it against their previous wielders or use it along them for a common goal

Arcane Plunder

Starting at 1st level, you are able to steal spells from others.

As an action, you may try to steal the magic of a creature you are currently touching, forcing them to make a Charisma saving throw against you spell save DC.

If they fail you steal a spell that they know and you are able to cast. The target loses the ability to cast that spell temporarily, regaining it after 1 minute, or instantly once you cast it. You however, retain that spell until you cast it. You use your own spell slots to cast stolen spells.

You can target specific spells that you know the target has. If you do not know any, you steal a random spell. Stolen spells count as Sorcerer spells for you, and you cannot steal a spell if it is part of an innate spellcasting ability or it requires a component that you cannot immediately provide.

You may only steal a single spell at a time, and the spell must be of a level for which you possess spell slots. If you steal a second spell before using the first, you lose your use of the first one.

You may steal a spell from a willing creature without them rolling.

You may only steal a spell from a creature once, then you cannot steal spells from that creature again until you finish a long rest.

Spell Imprint

 Starting at 6th level your ability to hold onto the magic you steal is strengthened.

You gain the ability to store slivers of spells as your own, not losing them after casting them. You can store a number of spells equal to your Charisma modifier. Whenever you steal a new spell and decide to store it, it replaces the oldest stored spell you currently hold.

Sorcerous Thief

 At 14th level your innate magic is reinforced by the spells you steal. You regain a number of sorcery points equal to the level of the spells you steal. This feature can be used once per long rest.

Total Usurpation

 At 18th level, your ability to steal magic reaches its peak. You become able to permanently deprive a creature from one of their spells.

When you steal a spell, you can spend a number of sorcery points equal to the level of that spell to completely appropriate it. The stolen spell is added to your list of known spells and the target loses it permanently.