Mirali
The Mirali are a collective, spiritual, humanoid race.
Energy crystals
The home planets of the Mirali are covered in living crystals which are predominantly reddish-purple in colour, and which can store vast amounts of energy within. The Mirali evolved alongside them, and have a spiritual connection with the crystals which can be considered a form of primitive telepathy.
The Mirali use the crystals as a construction material to build both land-based structures and spacecraft.
Because of their close connection to the crystals and their reliance on them as a species, the Mirali like to stay close to home. While they have expanded outwards in a colonial manner, their colonization is far more steady and conservative than other races. This is because, when colonizing a new planet, they have to give time for the crystals to grow across the planet, essentially requiring the planet to be partially terraformed before the Mirali can establish a permanent presence.
Due to their tendency to transform every place they inhabit into a crystalline environment, and their spiritual connection to the crystals, they are simply seen as a highly dedicated, religious race - sometimes even cultist.
Culture
Almost every aspect of the Mirali culture revolves around the use, protection, and appreciation of the empowered crystals. They thrive on being a peaceful, guided, safe culture, crediting the crystals with bringing them this good fortune, exhibiting incredible fanaticism and faith to the other races.
Out of all the races, the Mirali tend to be the most humble and submissive, only acting in aggression when their way of life or the natural order is threatened. While generally quite passive, they are fiercely defendant of their space, and dislike trespassers.
Technology
The Mirali base most of their actual technology on the power generation that the crystals provide. They use the crystals for protection, energy, obstruction, and even weaponry. Their spaceships are also made from the crystals, which are able to slowly regrow in order to repair and regenerate damaged sections of hull.
Aside from the crystals, it's actually quite unclear exactly where the Mirali stand with technology. They don't appear to use any sort of tangible computer or mechanical types of technology, or radio/telecommunications. It's assumed that almost every function that an elevated galactic civilization requires to exist is served simply by utilizing the power of the crystals. This also serves as the Mirali's main weakness, since the crystals can be destroyed and the Mirali struggle to survive without them.
Background information
The Mirali's use of crystals as a power source was initially inspired by the Draenei from World of Warcraft, as well as Ancient technology from Stargate. The race can be seen as effectively mixing elements from both of these.