Killer Iron skeleton

An Iron skeleton who holds an iron sword and a shield. Iron skeletons kill hostile mobs using advanced AI (shields) he also knows when he is overpowered and retreats. while retreating his legs turn around and move away while the top attacks pursuers. When the Iron skeleton is threatened by a player it spins it's top half very fast. When an arrow has been shot at it when it is in this mode, it would be ricocheted dealing no damage. While in this mode it only takes 80% of melee damage and when a player or mob enters the rotation radius it takes 6 damage per half-second. However, when spinning it takes up a 3 by 3 by 3 cube and can only jump up a half block. while not in this mode it can go 75% faster and jump up 3 blocks. If it gets in water it gets corroded and cannot enter this mode, it also can not use it's shield.