Saboteur

You have a particularly shady past dealing in the art of sabotage. Whether it's traps, arson, or the general destruction of those who stand in your way, your the go-to person for those around you. Rogues who follow this archetype are often specialists that leverage time and preparation to ensure things go their way.

Bonus Proficiencies

Beginning when you choose this archetype at 3rd level, you gain proficiency in any two tool sets.

Bombadier

Starting at 3rd level, you can create and utilize explosive devices you prepare in your off time.

Each device takes 10 gp, an hour to craft, and a successful DC 15 Intelligence check using one of the tool sets you gained proficiency in when you chose this subclass. If you fail this check by 5 or more you lose half the materials used to craft the device and your attempt fails. If you succeed by 10 or more, the device is improved and you can incorporate another devices effects into the one you created. 

You can have a number of these incendiary devices equal to your Proficiency Bonus made at a time. Each device has a 30 ft. pull cord used to detonate each device as an Action.

You can choose from the following list of devices:

Donia's Bile. This device erupts in a burst of sticky flame when detonated covering a 15 ft. radius cube and igniting any flammable objects that aren't being worn or carried. Any creature in the area must make a Dexterity Saving Throw equal to 8 + your Proficiency Bonus + your Intelligence modifier being covered in the sticky, flaming liquid catching fire and taking 1d6 Fire damage and catching on fire taking an additional 1d6 Fire damage at the ending of each of their turns unless they use an action to put out the flames on a failure, or taking 1d6 Fire damage but not catching on fire on a success. The sticky flames coat the ground where the device explodes and continue to burn for 1 minute. Any creature who ends their turn in the area takes 1d6 Fire damage. 

Xeno's Drum. This concussive device surprises and pushes those in caught by it. This device explodes in a 10 ft. sphere pushing any object not being worn or carried 5 ft. away. Any creature within the sphere when the device goes off must make a Strength saving throw equal to 8 + your Proficiency Bonus + your Intelligence modifier taking 1d4 Force damage and be knocked Prone on a failure, or just 1d4 Force damage on a success.

Cover of Pnax. This device plumes out with smoke when activated, heavily obscuring a 15 ft. sphere, spreading around corners, for 5 minutes or until a wind of moderate or greater speed (at least 10 miles per hour) disperses it.

Okesian seafoam. A viscous liquid explodes out coating the ground in a 5 ft. x 20 ft. line onto the ground in front of it. The area covered in this liquid becomes difficult terrain and whenever a creature enters the area for the first time on their turn or starts their turn in the area they must make a Dexterity Saving Throw equal to 8 + your Proficiency Bonus + your Intelligence modifier or fall Prone on a failure, or move normally on a success.

Kiss of Phai. This bomb emits puffs of horrendously, repulsive gas that temporarily poisons those unlucky enough to find themselves in its presence. The poisoned gas fills a 10 ft. radius hemisphere before dispersing into harmless inert gas. Creatures in the area when the device goes off must make a Constitution Saving Throw equal to 8 + your Proficiency Bonus + your Intelligence modifier or become Poisoned for 1 minute on a failure, or not become Poisoned on a success. They can remake this saving throw at the end of each of their turns. 

Grenadier

Starting at 9th level, you've learned to make your explosive more stable and they gain the Thrown property with a range of 30/60 and detonate upon impact. 

Additionally, the timers on your devices can now be up to 8 hours instead of 1 hour. 

Demolitions Expert

Starting at 13th level you've learned how to conceal and set triggers for your explosive devices. Whenever you attempt to conceal a device, you make a Stealth (Dexterity) check and can determine what physical stimulant, if any, will cause your device to trigger. 

Creatures who do not discover the device have disadvantage on any saving throws the device might impose.

You also gain expertise in one of the tools you picked with your Bonus Proficiencies.

Master Saboteur

By level 17 you've refined and mastered the techniques used to make your bombs. You can now make a device in half the time and for half the gold cost.
You can also make one of the following superior devices at the cost of two device slots instead of one:

Ilios's Smile. This device causes a blinding light and deafening sound to erupt and fill a 30 ft. sphere. Each creature in the area must make a Constitution Saving Throw equal to 8 + your Proficiency Bonus + your Intelligence modifier taking 4d4 Force damage and are Stunned until the end of their next turn on a failure, or taking 4d4 Force damage and not being Stunned on a success.

Phorus's Rain. This device rains burning alchemical reagents down on a 20 ft. cube below the device igniting flammable objects that aren't being worn or carried for 1 minute. Each creature in the area must make a Dexterity Saving Throw equal to 8 + your Proficiency Bonus + your Intelligence modifier taking 4d6 Fire damage and 4d6 Acid damage on a failure or half as much on a success. A creature that enters the area for the first time on it's turn or starts its turn in the area must make a Dexterity Saving throw equal to 8 + your Proficiency Bonus + your Intelligence modifier taking 4d6 Fire damage and 4d6 Acid damage on a failure or half as much on a success.

Verna's Oasis. This device is to revitalize those near it, filling a 10 ft. cube with rejuvenating aromatics that heal each creature that begin their turn in the area or enter the area for the first time on their turn for 4d6. The gas emitted from this device dissipate at the start of your next turn.