Ranger archetype

Infected Skirmisher

When you choose this archetype at 3rd level you enter a symbiotic relationship with a unnatural infestation, you gain the following feature: Your walking speed increases by 10ft

Infected arrow

At 3rd level your infection aids you in combat, allowing you to shoot a cursed arrow. when you make a ranged attack, you can fire a cursed arrow instead of a normal arrow, this arrow is made purely from the infestation living in your body and does not consume ammunition. A creature hit by the arrow must make a constitution saving throw against your spell save DC. On a failed save the target is cursed for up to 1 minute as the infestation starts rapidly eating them from the inside. At the start of each of the targets turns it takes 1D6 points of necrotic damage. A creature affected by the arrow can make a new saving throw at the end of each of their turns, ending the effect on a successful save. You can only have one target infected at any given time. You can use this feature a number of times equal to your Wisdom modifier, (with a minimum of once) and regain all expended uses on a short rest.

The damage increases to 2d6 at 7th level, 3d6 at 11th level and 4d6 at 15th level

Parasitic Hound

At 7th level you can use an action to summon a ferocious hound made from pure infestation. It lasts up to 10 minutes or until you dismiss it. The hound acts on its own, you do not use any actions to control it, but you as a player control it. The hound shares your initiative and takes it's turn directly after you. Once you use this feature you can't use it again until you finish a long rest.

Infested Garden

At 11th level your infection grows stronger and can mostly live on its own. As an action you can fire an arrow that creates a field of corruption. You choose a point within range and shoot an arrow of infestation, it creates a field 10ft in diameter, centered on where the arrow landed. A creature that starts its turn in the field or moves into the field must make a constitution saving throw against your spell save DC. On a failed save the infected area is considered difficult terrain and deals 5d10 points of necrotic damage. On a successful save, it is not considered difficult terrain and the creature takes half damage. If a creature is under the effect of the Infected arrow its effects are suppressed but a creature must make saves against the Infested garden at disadvantage.

As a bonus action you can expand or retract the field, stretching or pulling it back 5 ft across any adjacent surface that you can see. Alternatively, you can use your bonus action to have an infected area rise up and form a 5ft block in order to block of a cave entrance, doorway or to just provide you with cover during combat.

The garden lasts until you dispel it, move more than 300ft away from it or you use this feature again.

Vaccinate

At 15th level you can hone your infection to the benefit of others, as an action you can spread your infection to any creature within 30 ft of you, giving them the following benefits for 1 minute: They ignore all effects of the infested garden, resistance against necrotic and poison damage, increased walking speed by 10 ft and if they drop to 0 hit points they instead drop to one (this effect can only happen once). You must finish a long rest before you can use this feature again.