- Custom legendary shield item called Aegis (shield base item) - /aegis [player] command to give the item (permission: aegis.give) - Right-click to activate: absorbs ALL damage for 3 seconds - 20 second cooldown after activation - Bossbar shows active block duration (purple, counts down) - Bossbar shows cooldown timer (red, segmented, counts down) - Action bar messages for: activation, blocked damage, cooldown warning, ready notification - Sounds on activation, block, and cooldown end - CustomModelData 1001 on the shield item for resource pack texture - Cleanup all bossbars and variables on player quit - Paper 1.21.4 server