Alley 'Knight' may be an ironic title for such an underhanded wretch, but those whose morals do not blind them can see the potential in this ally. The Alley Knight disregards honour and nobility, and instead focuses on a more 'pragmatic' strategy: below the belt, in the back, and most importantly, before they see it coming. The Alley Knights not only champion these despicable tactics, but pride themselves on them. While generally focused around debuffing enemies with crippling poisons and blinding powders, the Alley Knight can wield a variety of weapons of choice and tools for a fast, flexible fighting style, with an extra venomous bite that they never see coming.

Where it Hurts

Starting at Level 3, at any point, you can apply a hidden debuff*, called 'Where It Hurts', that only Alley Knights can perceive, to up to 3 target creatures or characters you can see. Creatures of the same type as one of the targets automatically receive the debuff as well. Tiny creatures cannot be targeted. You can use a round to choose a language you can speak and a target with the 'Where it Hurts' debuff. Any character or creature that can both see the target and speaks your chosen language can perceive 'Where it Hurts' on the target, as well as all other creatures visible to them of the same type as the target.

Where It Hurts: Any character or creature than can perceive this debuff on a creature or character can choose to substitute their attacks, damaging abilities, or single-target spells on that target for a 'Where it Hurts' version, which applies all it's regular effects, but has disadvantage to hit, and completely ignores Damage Resistances, as well as causing it to deal an additional point of damage the same type that it deals for every 10 points of damage it deals, increasing to 1 for every 8 at Level 6, 1 for every 6 at Level 10, 1 for every 4 at Level 14, and 1 for every 2 at Level 17. If the damage is split between multiple types, each type deals it's own bonus damage if applicable. All damage inflicted by a 'Where it Hurts attack' scale with the abilities of the attacker. After the first 'Where it Hurts attack' hits a target, the debuff is consumed, and cannot be applied to the same character or creature again until they heal from the damage.

*Where it Hurts is hidden to regular checks, but can be detected by magical means.

Fight Dirty

Starting at Level 3, you can use a round to improvise, harvest, or take any available or harvestable substance you can see within 2ft, and either keep it, use it, or attack with it if you know how, applying it's normal effects, but it's source cannot be harvested for that particular substance afterward if it had a harvest time longer than one round or 5 seconds. If the substance is an Injury poison, it can be both applied and attacked with in the same round if an applicable weapon is equipped. If harvesting a substance from a creature, you must have knowledge of both the substance and the creature, or assistance from a character(s) who does.

Swift and Brutal

Starting at Level 9, any character or creature that would suffer the effects of a poison or be inflicted with a condition due to your actions has disadvantage on their saving throws. 

Quick Coating

Starting at Level 13, you can use the Bonus Action granted by your Cunning Action to reapply poison to 1 weapon with the Thrown property or 5 pieces of Ammunition, or take the Use an Object action. After successfully attacking with a poisoned weapon in melee, you can make a Sleight of Hand (Dexterity) check; on a 15 or higher your weapon's current poison is not used up. This can only be used once per applied poison dose.

What Him 'Em

Starting at Level 17, while you aren't incapacitated, you can apply the effect of any poison you have available to a target, an item, or surface you can see within 10ft. Using this ability is completely undetectable by any creature or character than cannot see you. This ability activates no checks or saving throws, and ignores all resistance. If the target is immune to poison, it is inflicted with the poison's effects but avoids damage and is not afflicted with the Poisoned condition. Once you use this feature, you can't do it again until after a short or long rest. Non-magical checks that would detect this action do not.