Donalo Sandomere is a grizzled man, with the creased face of a farmer, but his gray-streaked beard is oiled and trimmed to a point, in the style of Tairen nobility. He wears a garnet in his left ear.
Donalo is among the strongest Asha'man, described a bit weaker in saidin only to Rand, Logain and Narishma. He has the Talent to read residues and so he is able to track and open a gateway to a place were a former gateway was opened before.
Sandomere is in the audience when Rand al'Thor addresses the Asha'man, and he participates in the battle at Dumai's Wells. He watches Rand select the Asha'man to accompany him back to Cairhien.
He is one of the Asha'man in Rand's army in Illian. Rand notices him, and thinks he looks familiar.[verify] When the fifty-one sisters sent to the Black Tower are captured and bonded by the Asha'man, he bonds Ayako Norsoni.
Several Dedicated, including Sandomere, Androl Genhald, Canler, Evin Vinchova, Mezar Kurin, and Welyn Kajima, meet with Logain Ablar. Sandomere reports that Atal Mishraile is receiving private lessons from Mazrim Taim. Toveine Gazal doubts that Donalo Sandomere is his real name. 
Linked, Sandomere and Ayako weave Fire to incinerate the corpses of Trollocs and Myrddraal. They accompany Rand to his meeting with the Daughter of the Nine Moons. Ayako waits a few miles away with the Saldaeans and most of the others while Sandomere is one of the six who accompany Rand to Lady Deirdru's manor. Afterwards, Nynaeve al'Meara Heals Sandomere's injuries. It is learned that he has been raised to full Asha'man status.
During the Last Battle, Donalo appears again, him and Ayako both having been turned to serve the Shadow. Together with several other Darkfriend channelers, such as Alviarin Freidhen and Atal Mishraile, he is lured into an Ogier stedding through a clever trick designed by Androl Genhald and Pevara Tazanovni.
He is presumed to be alive and kept a captive in Stedding Sholoon.