The Caped Crusader

My version of the Caped Crusader Rogue Subclass. No copyright infringement intended.

Level 3: Bat-Infusions

When you choose this archetype at 3rd level, you gain the ability to imbue mundane items with certain magical bat-Infusions. Whenever you finish a short or long rest, you can touch a nonmagical object and imbue it with a bat-Infusion, turning it into one of the magic items listed here: Cape of Memory Cloth, Cowl of Shadows, Grapnel Gun, Light Disruptor, Oceanic Repellent Bat Spray, Reverse Batarang (Belt pouch of 3), Sonic Batarang (Belt pouch of 3), Smoke Pellet (Belt pouch of 3). Your bat-Infusion remains an item indefinitely, but vanishes when you die.

 You can have one bat-Infusion active at a time. You can one more bat-Infusion active at 9th, 13th and 17th level. You can then infuse more than one nonmagical object at the end of a short rest. If you try to exceed your maximum number of bat-Infusions, the oldest bat-Infusion immediately ends, and then the new bat-Infusion applies.

Level 3: Brutal Martial Arts

Starting at 3rd level, you can roll a d4 in place of the normal damage of your unarmed strike, which gains the finesse property. When you use the Attack action with an unarmed strike on your turn, you can make one unarmed strike as a bonus action. 

 Additionally, you don't need advantage on an attack roll to use your Sneak Attack against a creature that is frightened or grappled. All other rules for Sneak Attack still apply to you.

Level 3: Eye For Detail

At 3rd level, you can use a bonus action to make a Wisdom (Perception) check to spot a hidden creature or to make an Intelligence (Investigation) check to uncover or decipher clues.

Level 9: Contingency Planner

At 9th level, you develop the ability to swiftly deduce certain information about a creature's offensive and defensive capabilities. As an action, choose one creature you can see within 60 feet of you. You learn the following details about its game statistics: condition immunities, damage immunities, resistances and vulnerabilities, legendary actions and resistances, and saving throw proficiencies. 

 At the DM's option, you might also deduce one of the creature's flaws or special traits, if it has any. 

 Once you use this feature, you can't use it until you finish a short or long rest.

Level 13: Batsuit Mastery

At 13th level, you gain proficiency in medium armor. In addition, while wearing a suit of armor, you never have disadvantage on Dexterity (Stealth) checks for wearing it, and you gain a +5 bonus to Constitution saving throws against being exhausted.

Level 17: Aura of The Dark Knight

At 17th level, you can use a bonus action in dim light or darkness to emanate a menacing aura until your concentration ends (as if concentrating on a spell). The aura extends 10 feet from you in every direction, but not through total cover. 

 Each creature of your choice that has 50 hit points or fewer is frightened by you.