During the Aeon of Strife
Temlaa was a protoss warrior and historian of the Shelak Tribe near the end of the Aeon of Strife. His duties included guarding xel'naga relics from attacks by hostile tribes. He looked up to his mentor, Savassan. From him he learned how to conceal his thoughts from other protoss (a common ambush technique during the time period).
The relics were poorly understood. They couldn't be studied using psionic powers (they had no minds to read, nor did they have a "psionic interface") but they were covered with writing - the protoss used psionics exclusively to communicate and did not understand the concept.
He is known to have possessed at least one "blood-kin", Raamar.
Savassan believed that the writing could be deciphered, if only he could study them. He announced that he would leave the Tribe, taking Temlaa with him. He copied as many inscriptions as he could onto animal skins (parchment) and carried them with him.
The Psychic LinkEdit
During their travels, the pair stumbled into a cave full of Khaydarin Crystals. Accessing them enabled the pair to psychically link to each other (an ability lost during the time period). Over time, they found they were not overwhelmed by the crystals and could access the psionic link without being near the crystals.
As Savassan and Temlaa studied the crystals, they began to understand the symbols on the relics. Savassan seemed to have a greater understanding of the symbols, but it was Temlaa who made the next breakthrough. In one case, he "grabbed" a damaged stone tablet in a dream, causing it to become whole. He memorized the symbols and woke up to write them down so Savassan could interpret them. They held a description of a place that held even more xel'naga relics. The two mystics continued to have more directed dreams, hoping to find the archive of relics.
The two protoss traveled to the location indicated in their dreams, finding a flat barren area with a large number of khaydarin crystals. They attempted to access the crystals and discovered they contained information, but had to be accessed in the right order. Savassan solved the Perfect Ratio problem, letting him know which crystals to access, and in which order. An artificial cavern in the ground opened itself up to the two protoss.
Within the cavern they discovered several dessicated "dead" protoss, all from different Tribes, connected to organic wires. Temlaa was particularly terrified by this discovery. They walked through a maze until they found the heart of the huge cavern, where they found a very large crystal which made a sound like a beating heart.
Savassan attached himself to the vines, which caused the huge crystal to glow magenta. Savassan immediately began to wither, resembling the other "dead" protoss. Temlaa quickly used the console to free Savassan, who immediately began to heal, physically and mentally. Savassan said he and the crystal "shared things" and now he knew the path to healing. He told Temlaa that "we don't need the Xel'Naga, we only need each other".
Eventually, Khas' actions brought about the end of the Aeon of Strife.