
Below 40% HP, summons two Aureus Spawns before it teleports. Starts firing sets of four Astral Flame Crystals at 80% life, which increases as Astrum Aureus loses life. Time spent in its recharging phase decreased. Gains movement and jump speed as its life decreases. Gains the ability to jump through blocks.
Below 50% HP, cycles through all attacks 50% faster. Astrum Aureus is in its recharging phase when it teleports, preventing it from hitting the player when it does so. These Flame Crystals home in on the player after two seconds and, after three more seconds pass or they get close to the player, lose their homing ability and gradually accelerate, eventually flying off screen. If Astrum Aureus is below 75% life, before returning to its recharging phase, it will instead stand still and fire two consecutive Astral Flame Crystals upwards, then teleport close to the player. Astrum Aureus performs this attack three times before returning to its recharging phase and repeating this attack cycle. When Astrum Aureus lands, it fires a laser blast at the player. If the player moves under it, it slams down, changing its horizontal speed to try to land on them. Makes a far and tall jump towards the player. The number of lasers fired per blast increases as Astrum Aureus loses HP, up to 4. During this attack, Astrum Aureus can swim through blocks. Astrum Aureus will fire eight laser blasts before transitioning to its next attack. Crawls toward the player, firing pairs of lasers at them.
If Astrum Aureus is alive when it becomes daytime, it will enrage, drastically increasing the speed it moves and jumps and completely removing its recharging phase.
All of its attacks inflict the Astral Infection debuff. The time it spends in its recharging phase decreases as its life decreases. After several seconds, its flames will ignite and it will begin to attack the player, cycling through a specific attack pattern before re-entering its recharging phase and repeating the attack cycle. While recharging, Astrum Aureus deals no contact damage and has no defense. When first summoned, Astrum Aureus will be in its recharging phase, indicated by the lack of astral flames. Astrum Aureus does not spawn on its own and must be summoned at Night using the Astral Chunk in the Astral Infection biome.