Custom Join By S1rOutcast

summon falling_block ~ ~1 ~ {Block:stone,Time:1,Passengers:[{id:falling_block,Block:redstone_block,Time:1,Passengers:[{id:falling_block,Block:activator_rail,Time:1,Passengers:[{id:commandblock_minecart,Command:gamerule commandBlockOutput false},{id:commandblock_minecart,Command:fill ~2 ~-3 ~-1 ~5 ~-1 ~1 stained_hardened_clay 13 hollow},{id:commandblock_minecart,Command:fill ~2 ~-2 ~-1 ~5 ~-2 ~1 stained_glass 13 0 stained_hardened_clay},{id:commandblock_minecart,Command:/scoreboard objectives add join stat.leaveGame},{id:commandblock_minecart,Command:"/tellraw @a [\"\",{\"text\":\"1CMD\",\"color\":\"dark_purple\",\"bold\":true},{\"text\":\" Custom join\",\"color\":\"green\",\"bold\":false},{\"text\":\" by S1rOutcast!\",\"color\":\"dark_aqua\"}]"},{id:commandblock_minecart,Command:fill ~3 ~-2 ~ ~4 ~-2 ~ chain_command_block 5},{id:commandblock_minecart,Command:setblock ~3 ~-2 ~ repeating_command_block 5},{id:commandblock_minecart,Command:blockdata ~4 ~-2 ~ {auto:1,Command:/scoreboard players set @a join 0}},{id:commandblock_minecart,Command:blockdata ~3 ~-2 ~ {auto:1,Command:"/execute @a[score_join_min=1] ~ ~ ~ /tellraw @a [\\\"\\\",{\\\"text\\\":\\\"JOIN \\\",\\\"color\\\":\\\"dark_purple\\\",\\\"bold\\\":true},{\\\"selector\\\":\\\"@p\\\",\\\"color\\\":\\\"green\\\",\\\"bold\\\":false},{\\\"text\\\":\\\" has joined!\\\",\\\"color\\\":\\\"dark_aqua\\\"}]"}},{id:commandblock_minecart,Command:setblock ~ ~ ~1 command_block 0 0 {Command:fill ~ ~-3 ~-1 ~ ~ ~ air}},{id:commandblock_minecart,Command:setblock ~ ~-1 ~1 redstone_block},{id:commandblock_minecart,Command:kill @e[type=commandblock_minecart,r=1]}]}]}]}