Overflow Sorcerer

 When the Overflow Sorcerer casts a spell, it absorbs extra magic from the Great Wheel. When magic from the outerplanes flows to the Outlands, the Outlands reject the magic because it would desturb the balance(the outlands is the plane of true neutral). The overflow sorcerer uses this magic, the more weave  the Overflow Sorcerer uses, the more he can absorb.

Magic Absorb

Overflow. Whenever you cast a spell using a spell slot, your Overflow Damage Modifier increases based on the level of the spell slot used:

1st-level spell: +1d4
2nd-level spell: +2d4
3rd-level spell: +3d4
4th-level spell: +4d4
(and so on)

Whenever you cast a damaging spell, it deals additional damage equal to your current Damage Modifier. This extra damage is the same damage type as the spell.

Your Overflow Damage Modifier is cumulative and never decreases during combat. For example, if your modifier is 0 and you cast a 2nd-level spell, your modifier becomes 2d4. If you then cast a 1st-level spell, that spell deals 2d4 extra damage, and your modifier increases to 3d4. The next damaging spell you cast deals 3d4 extra damage, after which the modifier increases again according to the level of the spell slot used.

Your Overflow Damage Modifier resets to 0 when combat ends or when you don't use a spell for 1 round.

Lore:

When magic from the Outer Planes floats to the Outlands, the Outlands rejects it because the Outlands is True Neutral and if extra magic were to be added it would destroy the balance. The Overflow Sorcerer uses this magic. If a Overflow Sorcerer uses the weave it can absorb extra magic that is close to the Outlands. The more weave the Overflow Sorcerer uses the more magic the Overflow Sorcerer can absorb. That's why the Overflow Sorcerer get's extra dice from a lvl 5 spellslot then a lvl 1 spellslot. The Damage Modifier does not reset, if ur damage modifier was 3d4, that extra 3d4 would just get the 3d4 back, but if u got that damage with a lvl 3 spellslot the lvl 3 spellslot could absorb 3d4 extra damage.

Note for DM: if ur campaign revolves around a creature in the Outer Planes getting very powerfull, u can make the damage dice 1d6 instead of 1d4, because there is more magic.

Trade

The Overflow Sorcerer can trade 2d4 dice of their Damage Modifier in for 1 sorcerer point.

Damage Transfer

The Overflow Sorcerer can use reaction to add the dice of the Damage Modifier to the spell of an ally, this does not reset the Damage Modifier but also does not increase the Damage Modifier.

Planar Drain

As a bonus action, you can choose one creature you can see within 120 feet to become your Drained Target. Instead of drawing magic from the Outlands, you use weave from the plane around your target.

While a creature is your Drained Target, whenever it casts a spell that deals damage, reduce the damage dealt by an amount equal to your current Damage Modifier. Roll the dice in your Damage Modifier and subtract the total from the spell's damage. If this reduces the damage below 0, the excess becomes force damage dealt to the caster instead.

The debuff ends if the Drained Target goes out of the 120 meter radius, the Damage Modifier resets to 0 or the Overflow Sorcerer chooses a different target.