UHC Random Player Kill Switch

summon FallingSand ~ ~1 ~ {Block:stone,Time:1,Passengers:[{id:FallingSand,Block:redstone_block,Time:1,Passengers:[{id:FallingSand,Block:activator_rail,Time:1,Passengers:[{id:MinecartCommandBlock,Command:gamerule commandBlockOutput false},{id:MinecartCommandBlock,Command:setblock ~1 ~-4 ~0 command_block 0 replace {Command:"/kill @r[m=0]"}},{id:MinecartCommandBlock,Command:setblock ~1 ~-5 ~0 chain_command_block 8 replace {Command:"/setblock ~ ~1 ~ minecraft:bedrock",auto:1}},{id:MinecartCommandBlock,Command:setblock ~1 ~-6 ~0 chain_command_block 8 replace {Command:"/fill ~ ~ ~ ~ ~1 ~ minecraft:grass",auto:1}},{id:MinecartCommandBlock,Command:setblock ~1 ~-3 ~0 stone_pressure_plate 0},{id:MinecartCommandBlock,Command:kill @e[type=ArmorStand,name=STRCMD]},{id:MinecartCommandBlock,Command:setblock ~ ~ ~1 command_block 0 replace {Command:fill ~ ~-2 ~-1 ~ ~ ~ air}},{id:MinecartCommandBlock,Command:setblock ~ ~-1 ~1 redstone_block},{id:MinecartCommandBlock,Command:kill @e[type=MinecartCommandBlock,r=1]}]}]}]}