summon marker ~ ~-0.5625 ~ {Silent:1b,Invulnerable:1b,Tags:["katter.theron.spawner"]}

kill @n[type=illusioner,tag=katter.theron.boss]
kill @n[type=block_display,tag=katter.theron.orb]
kill @e[tag=katter.theron.boss.minion,distance=..150]
kill @s