So here are the commands for the bosses!
These are to spawn the custom mobs (put commands in the command blocks, with a button on the command block):
Boss: summon Zombie x y z {CustomName:"Boss Name Here",Equipment:[{id:276,tag:{ench:[{id:16,lvl:30}]}},{id:313,tag:{ench:[{id:34,lvl:99}]}},{id:312,tag:{ench:[{id:34,lvl:99}]}},{id:311,tag:{ench:[{id:34,lvl:99}]}},{id:310,tag:{ench:[{id:34,lvl:99}]}}],Attributes:[{Name:generic.maxHealth,Base:350.0}],ActiveEffects:[{Id:1,Amplifier:1,Duration:1000000,Ambient:1},{Id:12,Amplifier:2,Duration:1000000,Ambient:1},{Id:1,Amplifier:2,Duration:1000000,Ambient:1}]}
Minions: summon Zombie x y z {CustomName:"Name Here",Equipment:[{id:276},{id:313},{id:308},{id:307},{id:310}],ActiveEffects:[{Id:1,Amplifier:1,Duration:1000000,Ambient:1},{Id:12,Amplifier:2,Duration:1000000,Ambient:1}]}
summon Skeleton x y z {CustomName:"Name Here",Equipment:[{id:276},{id:313},{id:308},{id:307},{id:310}],ActiveEffects:[{Id:1,Amplifier:1,Duration:1000000,Ambient:1},{Id:12,Amplifier:2,Duration:1000000,Ambient:1}]}
That's all for the custom mobs. ( I would suggest spawning 6-8 minions) You can change the weapon of the mobs by changing the first equipment id. 276 is a diamond sword, a diamond axe is 279.
These are to spawn the custom mobs (put commands in the command blocks, with a button on the command block):
Boss: summon Zombie x y z {CustomName:"Boss Name Here",Equipment:[{id:276,tag:{ench:[{id:16,lvl:30}]}},{id:313,tag:{ench:[{id:34,lvl:99}]}},{id:312,tag:{ench:[{id:34,lvl:99}]}},{id:311,tag:{ench:[{id:34,lvl:99}]}},{id:310,tag:{ench:[{id:34,lvl:99}]}}],Attributes:[{Name:generic.maxHealth,Base:350.0}],ActiveEffects:[{Id:1,Amplifier:1,Duration:1000000,Ambient:1},{Id:12,Amplifier:2,Duration:1000000,Ambient:1},{Id:1,Amplifier:2,Duration:1000000,Ambient:1}]}
Minions: summon Zombie x y z {CustomName:"Name Here",Equipment:[{id:276},{id:313},{id:308},{id:307},{id:310}],ActiveEffects:[{Id:1,Amplifier:1,Duration:1000000,Ambient:1},{Id:12,Amplifier:2,Duration:1000000,Ambient:1}]}
summon Skeleton x y z {CustomName:"Name Here",Equipment:[{id:276},{id:313},{id:308},{id:307},{id:310}],ActiveEffects:[{Id:1,Amplifier:1,Duration:1000000,Ambient:1},{Id:12,Amplifier:2,Duration:1000000,Ambient:1}]}
That's all for the custom mobs. ( I would suggest spawning 6-8 minions) You can change the weapon of the mobs by changing the first equipment id. 276 is a diamond sword, a diamond axe is 279.