Lord Barst Berengarsson was an Imperial general known for his cunning and his prowess in battle.
In the assault on Urû'baen, he wielded a massive spiked mace and seemed impervious to harm, even to the formidable magical attacks of the elves, due to being empowered by one or more of Galbatorix's cache of Eldunarí. He effortlessly cut a swathe through the Varden's ranks of humans, dwarves, Urgals, and elves. Because of Galbatorix's use of "The Name" (the name of ancient language), Barst was impervious to magic.
Islanzadí and her elves fought a hopeless battle against Barst, their weapons seemingly powerless against his invulnerability. After Barst slaughters many dozens of elves, Islanzadí engages Barst in a titanic and spectacular duel, but due to the sheer power of his collected Eldunarí and wards, Islanzadi fell to his mace. Barst's victory over the elven queen sent many of the Varden into panic, the majority of them scattering as the Imperial troops pushed the Varden back. Ultimately, the combined efforts of Roran, Nar Garzhvog, Jörmundur, Grimrr Halfpaw, Angela, Orik, Däthedr, along with hundreds of Varden soldiers, Kull, Werecats, and Elves were needed to finally bring Barst down – alongside a barrage of stones thrown from dwarven war machines and a hail of javelins to incapacitate the Imperial lord– though not without horrendous casualties for the combined troops. Roran, despite grievous injury, cracked the Eldunarí stored within Barst's armor, killing him.
Barst parallels General Grievous from Star Wars in quite a few ways. Both are successful and feared generals in the service of their respective saga's antagonistic forces. (To the Broddring Empire under the rule of Galbatorix and the Confederacy of Independent Systems that was masterminded by the Sith) Both are physically imposing and known to also have a high body count under their own belts. Whilst neither is a true practitioner of the mystic arts, they still manage to pose a significant threat to those who do, though they have some sizable help in the form of enhancements from their superiors/allies. (Galbatorix managed to make Barst impervious to magic by of "The Name" of the ancient language as well as strengthening him with the use of at least one cache of Eldunari. Grievous was turned into a cyborg by the Separatists which gave him augmented physical capabilities and was also trained in the art of lightsaber combat by Count Dooku.) Both would eventually be slain during an important battle where a key stronghold of the villains was under attack (the assault on Urû'baen and the Battle of Utapau) by a major heroic character who was one of the major leaders for his side during the battle (Roran and Obi-Wan Kenobi) by attacking a key item within his armor (Roran cracked the Eldunari stored inside Barst's whilst Obi-Wan blasted Grievous' organ sac).