Like all Ogier, he is deliberate and methodical in his thought; haste leads to waste appears to be his people's motto. However, when roused to anger, he is an implacable enemy. He is 90 years old, at a stage of development roughly corresponding to that of a human boy in his late teens; he is considered very excitable by his people. Very well read, he is rarely without a choice bit of arcane history to offer, whether concerning humans or Ogier, and he carries books on his person at all times.
He left the stedding at a "young" age to the disapproval of his elders, wanting to see more of the world; he befriended Rand al'Thor in Caemlyn and accompanied the party from the Eye of the World to the Stone of Tear, witnessing the rise of the Dragon Reborn. From that point on, he accompanied Perrin to the Two Rivers and aided in its defense, and also fought at Dumai's Wells. Only recently have the two parted company: while Perrin headed into Ghealdan to deal with Masema Dagar, the Prophet of the Dragon, Loial agreed to take an Asha'man, Karldin Manfor, to visit the stedding, where the One Power cannot go (historically, the insane men of the Breaking visited the stedding to gain some reprieve from the spread of the madness). While visiting the stedding, he warned the Ogier that the Shadowspawn are using the Ways. Loial returned, since it is his ambition to write the definitive book about this turn of the Wheel's War of Power. When historians speak of Rand al'Thor, it will be Loial son of Arent son of Halan that they cite most frequently and most often.
Loial has frequently proven himself to be both brave and valorous, despite his humble assertions of being a scholar and writer. He has defended children and women against both Myrdraal and Trollocs in the Stone of Tear, traveled the Ways, protected the folk of the Two Rivers against close to impossible odds, and been among the few to dare the wrath of Rand al'Thor.
The other reason Loial is not likely to remain in a stedding is that his mother, in an attempt to settle him down, negotiated a marriage for him while he was away. In Knife of Dreams, his mother and Erith finally track him down, and he and Erith are married by Elder Haman. Loial had not felt ready for marriage, but, being very much in love with his bethrothed, was quite happy with this turn of events.