Brother Eliac was an older priest of Fener, in the early days of the formation of the Malazan Empire. Eliac had a tattoo of Fener's visage on his bearded face. He belonged to a temple devoted to the 'Great Boar' which was, presumably, located somewhere on Quon Tali.
Brother Eliac was the eldest of a group of two priests and two priestesses - all with facial tattoos of Fener - who intercepted Heboric, who possessed a full-body tattoo of the Boar marking him as "chosen".
Heboric was travelling between a temple of Poliel in Horan — eastward along the southern shore of Quon Tali — to the "Isle of the Cursed", aka Poliel's "Isle of the Blessed". Eliac addressed him as "Heboric of Carasin", and told him that Eliac and the others had been sent from Heboric's "family". By "family", Brother Eliac was referring to the quartet's and Heboric's home temple. The four had stopped Heboric as they wished him to return with them. Eliac urged Heboric to do so as the "family" was concerned about Heboric's behaviour and were afraid he was ignoring his "sworn obligations" to Fener.
Heboric, however, had his own path to which he felt called to attend to by Fener, himself. The four reluctantly accepted Heboric's decision not to return. But Brother Eliac first warned Heboric that his intention of visiting Poliel's "Isle of the Cursed" could only lead to death. Heboric, on parting from the others, said, "I, brother Eliac, trust in Fener".