Tau

The Tau were a new, fast-rising civilisation who were comparatively young in terms of the Warhammer 40,000 universe, having only become a starfaring race within the last few millennia. The Tau empire, we proposed, would be lodged deep in the Eastern Fringes, far from the most strongly held regions of the Imperium. This meant that although the Tau empire was tiny in comparison to the might of the Imperium or the numberless hordes of the Orks and Tyranids, it would be a big fish in a small pond. The Tau possessed an impressive grasp of technology and its armed forces were superbly equipped with the best weapons and armour their race could devise - grav tanks, energy weapons, armoured battle suits and so forth. The Tau race itself was highly focused and well-organised, following a rigid caste system based around the four elements of earth, air, fire and water. The Earth caste were builders, farmers and engineers, the Air caste were messengers, pilots and starship crews, the Fire caste were warriors with all that snazzy wargear, while the Water caste fulfilled the role of merchants and diplomats.

Here are some of the Tau's Warriors:

Fire Warriors: Fire warriors are the basic Troop type of the Tau forces, and you must include at least one unit in your army. Though they are neither especially tough or strong, their pulse rifles and carbines are ideal defensive weapons, capable of laying down a withering salvo of fire that can pin the enemy in place for heavier units to engage.

Pathfinders: Pathfinders are the forward scouts of a Tau force and are able to work themselves into prime spotting positions where they can use their Markerlights to enable those carrying heavier weapons to shoot with pinpoint accuracy.

Stealth Battlesuit: Powerful holographic disruption fields allow Stealth teams to sneak forward unobserved into advantageous firing positions before battle commences. They are hard to detect and their burst cannons are the perfect weapons for ambushing lightly armoured troops and attacking the flanks of vehicles.

Crisis Battlesuit: Together with the commander, these warriors form an HQ unit
on the battlefield and are capable of mounting an array of deadly weaponry
that can meet almost any threat and neutralise it.