Termidon Terman specific Eldritch Knight variant

http://homebrewery.naturalcrit.com/share/B1r84nwMW

The Complete Terman

Here is a link to a .pdf of the current Terman build:

http://homebrewery.naturalcrit.com/share/H1HNZSbDzW

Termen as adventurers

So you want to play a terman, but it is hard to come up with an origin story that  justifies your character leaving his well defended home tunnels.  Well, here are some ideas.

The Terman who would be king (or queen):

The first was already alluded to in the descriptions previously posted.  Termen who show great promise are often thrown out of their home colonies by jealous Kings and Queens who are afraid of them usurping the nest.  These are usually of the Archon class, but can be any class.  Others may simply wish to start on the path to being able to rule a nest some day.  In their society, the way this is done is to go out among other nests, and sometimes other races, to gain skills and followers in order to either challenge the existing royals of their original nest or another nest for leadership, or gather enough followers to start their own new nest.  All of this requires wealth and fame.

The not-so-quick and the dead:

Termen respond vigorously to a breach in their colony's defenses.  Termidons rush to the scene to block entry to invaders as other casts, led by Terrarch earth seal up spells that move earth and throw up wall of earth.  Often the breach is sealed behind the defenders, who give their lives to protect their home and nestmates.  This sacrifice is such a great honor, and the danger of attempting to rescue survivors outside the nest so great, that by their custom, all defenders caught outside are considered dead and mourned as heroes.  A terman of any cast that manages to survive, but is caught outside is dead to his colony and may not return.  They are simply called the "Lost" and wander in search of new purpose and to erase the shame of surviving as others fell. From this unfortunate beginning many a great terman has arisen.  Cut off from their home societies, they are far more likely to interact with other races and mingle in strange society.

The seeker:

Many castes much range widely, though usually underground for rare reagents (alchemists), creatures to tame (Swarm Lords, Theros, Slavers), or just new and powerful weapons.  The most often place to find them is travelling to dwarven cities, but their paths could lead anywhere.

The Forager:

This is the most common manner in which a terman finds itself outside of its nest.  Seasonally, they must undergo mass foraging raids.  These usually are aimed at the arborial cities of elves, but they will raid any promising source of well cured wood.  Wood with the taint of magic is a plus, and many a staff and wand have disappeared in a terman warren.  In the confusion of these raids, many can become separated.  Although they are not considered as "Lost", they do suffer a stigma if they need to break back into their own home tunnel complex.  For doing so may tip off invaders where entrances are hidden.

Terman Alchemist

Alchemists

Terman Alchemist:  These are the most powerful spell casters of the termen.  The power of their spells comes from their intimate knowledge of the arcane power inherent in many species and substances. 

There are good homebrew alchemists out there, but if you play a wizard with a focus on conjoring and pick spells based on acid or manipulation of form like those I picked for the defender you can create a wizard with the right flavor.  I will eventually make up this class properly, but they often have Myconid Sprouts as familiars and make use of their spores to make zombies of recently dead corpses in a manner akin to necromancers.

Minions and Metal Smiths

Minions

Minion or Termen Worker:  This caste does most of the work within colonies and aids in defense. They are small in size and very good at blending into the shadows and making no vibrations when they desire not to be noticed by task masters from the other castes. There is no truly applicable archetype of rogue, but Thief will do.  Just remember they are sneaky, not criminal.

Metal Smiths: When dwarves first allied themselves with termen, they shared their knowledge of metalworking with termen who at the time had a stone-aged technology.  The minions who were assigned to work with and learn from the dwarves soon formed their own caste within terman society.  Much as the consumption of elven magic morphed the bodies of termen into humanoid form, metal smiths have come to mimic their dwarven companions in many ways.  Their bodies are broader and taller than a normal minion, and, unique among termen, they grow lush beards of hair-like bristles.

They are fighters, but many are known as Dwarf-friends and have been given Dwarven Combat Training.

Archons- Elite warriors of termen society

Archons

Archon or Royal Termen  are the elite of terman society.  Most will spend their lives in service to the nest they were born into, drawing power from the spirit of the colony to augment their considerable physical skills.  Others will leave their home nests to seek adventure, building their fame and retinue, in order to mount a challenge for the rule of another existing colony or start their own.  Although termen of any caste can mount such a challenge if they gain enough renown, archons, with their larger physical size and domineering personalities are most likely to be successful. Male and female archons are as similar as the two sexes of any caste are, showing only minor differences in color and hair-like bristle patterns. After a female becomes a queen, she undergoes metamorphosis, her middle limbs becoming legs to aid in supporting her large, egg-filled abdomen.

They are Paladins, but they primarily worship their own colony as an entity and expression of their chief god.  They focus on spells that aid in commanding minions and those used for single combat with their peers. Think of them a bit like Dark Sun Templars.

Slaver- provider of thralls to augment the colony labor force

Slaver

Slaver: Through the application of poisons and fungal extracts, slavers bend the will of other creatures to serve the colony.  These may provide labor or be placed within warrens to defend the nest.

Use the assasin archetype with the following changes to reflect that they are not infiltrators:

 At 3rd level you gain the poisoner's kit.  In place of the disguise kit you gain the spell Charm Person 1/short rest.

 At 9th level you may use your fungal extracts to cast Geas 1/short rest

 At 13th level you may use your fungal extracts to cast Dominate Monster 1/short rest