Roguish Archetype Work in progress

Arcane Lockpick

A tiefling is caught red handed just as the bank vault yawns open, she runs inside only seconds before her pursuers and their complete shock to find her not in the vault. A gnome in a rope harness weaves a rats nest of primercord and wire on the ornate chest above which he dangles, he delicately touches the tips of two wires and the chest glows with runes that sizzle and smoke and die. The feylines can be cut as easily as a tripwire when you know what you're doing, a paralyzing spell undone just as one would real ties that bind. When you know what you're doing you can break into a building that doesn't exist.

No passage is barred and no barrier is impassable for the Arcane Lockpick, who so deftly subverts magic's esoteric nature with mechanical acumen; using no magic themselves, the Arcane Lockpick blends an intimate knowledge of arcana and tremendous technical skill to manipulate, disarm and destroy existing magic. Theres a world of hidden and locked away things, things that they don't want you to have, that they don't want you to see. You just have to know what you're doing.

Magic Hands

When you choose this archetype at 3rd level, you apply double your proficiency bonus to any checks you make using your Thieves Tools.

Defuse Arcana

At 3rd level you gain proficiency in the Arcana skill and while you are holding your Thieves Tools, you can use your action to attempt to end spells on a creature, object, or magical effect within 5 feet of you. Any spell of a level equal to or lower than your proficiency bonus on the target ends. For each spell on the target of a level higher than your proficiency bonus make an Intelligence (Thieves' Tools) check. The DC equals 14 + (2 x Level of the spell). On a successful check, the spell ends. You can use this ability one time, then you must complete a long rest before you can do so again. This increases to twice at 10th level and three times at 17th level.

Shout outs to my mans u/sandwichbear for excellent advice on the Defuse Arcana mechanic.

Breaking and Entering

At 9th level you can spend 1 minute using your Thieves Tools to pick the lock or otherwise tamper with a closed door, window, gate, or other entryway within 5 feet of you to create a connection between it and another entryway, at any distance, on the same plane of existence. You must have touched the destination entryway at least once before. For the duration, any creature can step into either entryway and exit from the other by using 5 feet of movement. The duration of the effect is 1 minute or until the entryway is closed. You can use this ability once, and then you must complete a long rest before you can do so again.

You can also use this ability to at any time while holding your Thieves Tools, over 1 minute, to create a connection between a chest, trunk, cabinet or other container within 5 feet of you and an extra dimensional storage space. Any contents you place in this space will still be there no matter what container you access it from next, the space can contain up to 6 cubic feet of nonliving material (2 feet by 2 feet by 1.5 feet). The effect lasts until you close the container or use this ability on another container.

Dimensional Trespass

At 13th level you when you are prevented from entering the portal or joining the teleportation effect created by another creature, object, or magical effect, you can use an action to make an Intelligence(Thieves Tools) to attempt to gain access to a current or recently terminated portal or teleportation effect. The DC equals 14 + (2 x Spell level). You can only attempt to access a portal or a teleportation effect for up to hour after the original spell has ended and you must be within 5 feet of the location of the target of the spell. On a succesful check the spell is recast as though you had cast it but only with the same destination as the original. You can use this ability one time and then you must complete a long rest before you can do so again.

Additionally, at 13th level using your Breaking and Entering class feature you can at any time while holding your Thieves Tools, over 1 minute, create a connection between an entryway within 5 feet of you and a long since abandoned extra dimensional living space. Any creature can enter or exit the extradimensional dwelling as long as the entryway remains open. While closed entrance to the extra dimensional space is invisble and intangible and the target entryway functions as normal. You can open and close the entryway as a bonus action while you are within 5 feet of it. You can create any floor plan you like, but the space can’t exceed 50 cubes, each cube being 10 feet on each side and the floor plan will always be the same after your first visit. The place is furnished and decorated as you choose, but the interior will always be worn and aged. Anything you place in this space will be there no matter from what entryway you access it next, but any furnishings and other objects created by this ability dissipate into smoke if removed from the space. The effect lasts until you close the entryway from the outside or use this ability on another entryway. When this effect ends any creatures inside the extradimensional space are expelled into the open spaces nearest to the entrance.