Mirrorkin Quick Fix
This is my attempt the fix the Mirrorkin Sorcerer from Valda's Spire of Secrets. This is only making basic adjustments, I personally still don't like it, but this version preserves most of the stuff from the original.
To be frank, use The Mirror Soul Sorcerer, I think it's better made (Texture-wise, You can flavour anything to be anything).
L01: Mirror Magic
When you choose this origin at 1st level, you can duplicate the magic that affects you. When a spell is cast targeting you or you are in the area of a spell’s effect, you can use your reaction to learn that spell. If the spell forces you to make a saving throw, you succeed, and the spell has no effect on you, you can’t learn that spell.
You can only learn a spell if it is of a level for which you have spell slots. You can learn 2 first-level spells using this ability, which don’t count against the total number of sorcerer spells you know. When you gain 2nd, 3rd, 4th, and 5th level spells, you can learn 2 spells for each of those levels, for a total of 10 additional spells known. The spells learned need not be from the sorcerer spell list, but count as sorcerer spells for you. You can use your action to forget a spell you have learned using this ability.
L01: Mimic Trait
As an action, you can choose a creature you can see within 60 feet and gain one item of your choice that they possess from the following list (even if they only possess it temporarily):
- One special sense, such as darkvision or tremorsense.
- One movement speed, such as a swim or climb speed.
- One skill, tool, or instrument proficiency.
- One damage resistance.
- Their accent, verbal tics, and mannerisms.
You can keep this trait as long as you are within 60 feet of the target, or until you use this ability again.
L06: Reflect Magic
When a creature casts a spell calls that for a saving throw to resist its effects and targets you or includes you in its area of effect, you can attempt to reflect the spell's energy back against its caster. Spend a number of sorcery points equal to the spell's level (1 sorcery point for cantrips). If you succeed on your saving throw against the spell, the caster must also make a saving throw against the spell, using their own spell save DC. On a failed save, the caster suffers the effects of the spell as if you had cast it and they had been the original target or been within the area of the spell.
L06: Reflect Might
As a reaction, when a creature targets you with a attack roll or saving throw, you can mimic the attacker's AC or saving throw (You are aware of what the value is). If the attack still hits or you still fail the saving throw, you take half damage and the other half is reflected back at the attacker. If the attacker is immune to the damage type, treat it as being resistance.
You can use this ability a number of times equal to your half your proficiency bonus, and regain all uses of it when you finish a long rest.
L14: Copycat
As an action on your turn, you can perform any action that has been performed by a creature (other than yourself) you can see within 60 feet within the last minute. Any prerequisites that would normally be required for the action (such as brandishing of holy symbols, spending of ki points, or consumption of items) are waived when you use this feature, unless it is a spell or required the use of a spell slot, in which case you must still expend the relevant spell slot and expensive material components, if any are required. If the ability forces targets to make a saving throw, you can use your sorcerer spell save DC.
Once you use this ability, you must finish a long rest before you can use it again.
L18: Perfect Duplicate
You learn the spells disguise self and mirror image if you do not know them already, and you can cast them at will, as a action or bonus action, without expending a spell slot.