Requirements

Alignment: Any evil or any chaotic.

Feats: Augment Summoning

Skills: Concentration (10 ranks), Handle Animal (10 ranks)

Spells: Ability to cast 4th level arcane or divine spells. Ability to cast either summon swarm or giant vermin.

Summary

Arthroparch is for the casters who want a little bit more extra damage and protections and don't mind insects to do that. This class is interesting as it takes advantage of swarms which are often not used by players in a capacity to defend or attack aside from Master of Flies or the Summon Swarm spells. It's a pretty good "Get Off Me" option as with a swarm of these size of creatures they can only be harmed by AoE and unless every town guard is carrying some AoE or splash option it may be quite hard for them to deal with the swarm directly as it's infesting them.

Role: Spell Tank

Characteristics: Spellcasters with protective armies of vermin shielding them

Source: Homebrew

Game Rule Information

The Arthroparch has the following game statistics.

Abilities: Casting stat is paramount obviously, Constitution is also super important so you can maintain concentration on the swarm, Dexterity

Alignment: Any Evil or Chaotic

Hit Die: d6

Starting Gold: N/A

Class Skills

The Arthroparch's class skills are Concentration (Con), Disguise (Cha), Escape Artist (Dex), Handle Animal (Cha), Hide (Dex), Intimidate (Cha), Knowledge (Arcana)(Int), Knowledge (Nature)(Int), Knowledge (Religion)(Int), Listen (Wis), Profession (Wis), Search (Int), Spot (Wis)

Skill Points at 1st Level: (2 + Int modifier) × 4

Skill Points at Each Additional Level: 2 + Int modifier

Class Features

All of the following are class features of the Arthroparch.

Weapon and Armor Proficiency: A Arthroparch is proficient with whatever they were already proficient with prior to taking levels in this class.

Affect Vermin Su: The arthroparch is able to apply his Handle Animal checks to call forth non-monstrous insects of the Vermin subtype and amass them around him. Although mindless creatures can never be turned friendly, they can be compelled to obey the arthroparchs mental and verbal commands through a brand of occultish synaptic suggestion. A vermin will never willingly come to the arthroparch's aid, but with the aid of a DC 15 Concentration check, the arthroparch may will it to do as he wishes. This ability allows the arthroparch to control a number of HD worth of vermin equal or lesser than four times the arthroparch's caster level through the use of Concentration checks at once. The arthroparch caster level is the highest caster level tied to his arthroparch levels. Although vermin has a neutral disposition towards the arthroparch and his allies by default, they will attack other creatures randomly and indiscriminately when no Concentration is applied unless dismissed, or otherwise the arthroparch is only able to give the most basic of commands when not using his Concentration. Using Affect Vermin, the arthroparch may call any normal sized insect within a hundred feet to him at will, and allows him to issue more complicated commands to vermins via his will, such as 'move precisely here' or 'defend me while I cast my spell'.

Poison Immunity Ex: At 1st level, the arthroparch's physique is guarded against the ill effects of poisons that stem from vermin sources

Giant Vermin Su: At 1st level, the arthroparch learns to engorge vermin to massive sizes through transmutation magics. Twice per day, he can increase the size of vermin that he has called to him; this functions like a giant vermin spell, with effective caster level of 10 + the arthroparch's level. Every odd numbered level after 1st, the arthroparch learns to use this ability an additional two times per day, up until 10 times per day at 9th level. Although not actually a summon, these giant vermin benefit from the bonuses gained by the Augment Summoning feat just the same.

Protective Swarm Su: Whether through personal neglect, rot or detritus, or simple powers of attraction, at 2nd level, the arthroparch learns to gather to him a swarm of all manner of airborne pests. This swarm is normally centered upon the arthroparch and grants concealment to ranged attacks. At first, the swarm reaches 5 feet around the arthroparch and deals 1d6 damage to any who seek to attack him or who linger within its radius of effect. The damage is both slashing and piercing; when damage reduction applies to the targets, pick the type more favorable to the arthroparch. While inside the swarm, the arthroparch gains effects that intensify as he gains levels.

Although centered around the arthroparch, the protective swarm is regarded as a creature of its own, starting out with 20 hit points at 2nd level and gaining 10 additional hp every level after as seen in Table 1-2: Swarm Progression. While in the swarm, the arthroparch enjoys limited protection against certain attacks. The first number of hp of damage equal to the amount of resistance the arthroparch has is absorbed by and dealt to the swarm, not unlike the stoneskin spell, but only applicable to area effect evocations. The swarm's damage reduction also applies to hostile creatures of the Swarm subtype. Furthermore the Swarm also has fast healing as indicated in Table 1-2 and regains that amount of HP per round.

The arthroparch may scatter and disperse the swarm if he wants to as a move action, but gathering it to him again takes 5d4 rounds regardless of how and why it dispersed. If the arthroparch is targeted by a gust of wind, the swarm will scatter immediately if he fails his Fortitude save. Otherwise, it is unaffected.

Aggressive Swarm Su: When the arthroparch reaches 10th level and the protective swarm he commands reaches its pinnacle, he can direct a portion of it to attack as well. With nothing but his will, he releases a portion of his protection in a 30 ft. cone. The swarm will pelt any in it with 5d6 slashing/piercing damage. Reflex DC 10 + ½ character level + Cha mod half. This attack functions as a breath weapon and requires a 1d4 round cooldown time.

Table 1-1: Arthroparch Progression

Level	Base Attack Bonus	Fort Save	Ref Save	Will Save	Special	Spells per Day
1st	+0	+2	+0	+2	Affect Vermin, Giant Vermin 2/day, Poison Immunity	—
2nd	+1	+3	+0	+3	Protective Swarm 1d6/5 feet	+1 level of existing arcane spellcasting class or +1 level of existing divine spellcasting class
3rd	+1	+3	+1	+3	Giant Vermin 4/day	+1 level of existing arcane spellcasting class or +1 level of existing divine spellcasting class
4th	+2	+4	+1	+4	Protective Swarm 2d6	+1 level of existing arcane spellcasting class or +1 level of existing divine spellcasting class
5th	+2	+4	+1	+4	Giant Vermin 6/day	+1 level of existing arcane spellcasting class or +1 level of existing divine spellcasting class
6th	+3	+5	+2	+5	Protective Swarm 3d6/10 feet	+1 level of existing arcane spellcasting class or +1 level of existing divine spellcasting class
7th	+3	+5	+2	+5	Giant Vermin 8/day	+1 level of existing arcane spellcasting class or +1 level of existing divine spellcasting class
8th	+4	+6	+2	+6	Protective Swarm 4d6	+1 level of existing arcane spellcasting class or +1 level of existing divine spellcasting class
9th	+4	+6	+3	+6	Giant Vermin 10/day	+1 level of existing arcane spellcasting class or +1 level of existing divine spellcasting class
10th	+5	+7	+3	+7	Aggressive Swarm, Protective Swarm 5d6/15 feet	+1 level of existing arcane spellcasting class or +1 level of existing divine spellcasting class

Table 1-2: Swarm Progression

Level	Swarm Radius	Swarm Max Damage	AC Bonus	Swarm HP (Swarm Damage Absorption)	Swarm Healing per round
1st	—	—	—	—	—
2nd	5 ft.	1d6	+1	20 (10)	2
3rd	5 ft.	1d6	+1	30 (10)	3
4th	5 ft.	2d6	+1	40 (10)	4
5th	5 ft.	2d6	+1	50 (10)	5
6th	10 ft.	3d6	+2	60 (20)	6
7th	10 ft.	3d6	+2	70 (20)	7
8th	10 ft.	4d6	+2	80 (20)	8
9th	10 ft.	4d6	+2	90 (20)	9
10th	15 ft.	5d6	+3	100 (30)	10
Swarm HP indicates the total amount of damage that the swarm can soak before scattering. The Swarm Damage Absorption in parenthesis indicates the amount of damage from a single attack that the swarm can soak. Damage over this amount is dealt to the Arthroparch. The swarm can only absorb damage of area effect evocations and blast effects like those of an acid flask or alchemist's fire. Also, any energy effect that doesn't specifically target you, like a lightning bolt for example, is also subject to this damage reduction.