As a Lich, he uses the typical strategy associated with the race (teleport around the map while attacking with magic from afar). While Azzrssil has powerful magic, he can be rendered weaker without much trouble. He attacks mostly with Ice Bolt, so stack your resistance to ice to superb and potions/rods of silence should make him unable to attack (only in vanilla Elona, Elona+ bosses have excellent resistance to hexes). More info in Azzrssil's page. A is guaranteed to spawn here as reward for slaying Azzrssil. (Elona+ only)