From WoWWiki

A mysterious swordsman on Mount Hyjal. He is strange for an Argent Dawn templar. He was apparently once a paladin, and perhaps still is, he wears no armor other than an ornate breastplate, which may be just for show. Andarin is a solid fighter and a good representive of member of the Argent Dawn.^{APG 151}

Once, Lightblade, wielding a bastard sword, was fighting a losing battle against a black dragon. He decided to make a final gamble to try to destroy the beast. He cast his famous spell, "Lightblade's Final Strike", sacrificing much of his life (enough to make him unconscious but not kill him outright). The attack delt much damage to the dragon with the potent and destructive attack.^{MM&M 66, 80, 81}

When he was a paladin Andarin invaded Undercity with fifty men to launch a surprise attack on Varimathras while the Banshee Queen was a way in Northrend. Once he went alone to the Undercity to set free some prisoners. While preparing to assault an abomination, he was discovered by a Forsaken, Trevor. The undead, who was once a priest of the Holy Light who refused to wield the shadow, proposed him a deal: Trevor wouldn't alarm the guards and Andarin would speak on Trevor's behalf with the Argent Dawn as accepting the priest in their ranks. The deal was made and while the paladin kept the guards at bay the undead freed two prisoners, a mage and a young girl that Trevor knew well.^{HPG 165, 170, 173, 179, 185}

Surname

• His surname is Lightblade likely due to the sword he wears. The runes on it spring to life, bathing the sword in holy fire.^{HPG 173}
• He was well known in Lordaeron because when Trevor discovers him in the Undercity (once Lordaeron Capital City), the forsaken recognizes him and refers to him by surname ("You have come here to free a prisoner, Commander Lightblade. I would have you set another person free."^{HPG 170}).