(2014, July 16) EnderBackpack

/scoreboard objectives add EChest dummy


/scoreboard players remove @a[score_EChest_min=1] EChest 1

/scoreboard players set @a EChest 2 {EnderItems:[{id:minecraft:ender_chest}]}

/execute @a[score_EChest=1,score_EChest_min=1] ~ ~ ~ /fill ~-5 ~-5 ~-5 ~5 ~5 ~5 air 0 replace ender_chest

/replaceitem entity @a slot.enderchest.26 minecraft:ender_chest