修正前
BlockEntityTag:{Text1:{bold:1b,clickEvent:{action:"run_command",value:"( /entitydata @e[type=Item,r=10,c=1] {Item:{Count:1b,tag:{display:{Lore:[\"古の魂が刻み込まれている\"]},ench:[{id:16s,lvl:15s}]}}} )"},color:"white",text:"==========="},Text2:{bold:1b,clickEvent:{action:"run_command",value:"( /execute @e[type=Item,r=10,c=1] ~ ~ ~ /particle iconcrack_88 ~ ~0.6 ~ 0 0 0 0.15 100 )"},color:"white",translate:"=%1$s=",with:[{color:"dark_gray",strikethrough:1b,text:"-古の魂-"}]},Text3:{bold:1b,clickEvent:{action:"run_command",value:"( /execute @e[type=Item,r=10,c=1] ~ ~ ~ /playsound mob.horse.skeleton.death @a ~ ~ ~ 1 1.2 0 )"},color:"white",text:"==========="},Text4:{clickEvent:{action:"run_command",value:"( /setblock ~ ~ ~ air )"},text:""}}

修正後
BlockEntityTag:{id:"Sign",Text1:"{\"bold\":true,\"color\":\"white\",\"clickEvent\":{\"action\":\"run_command\",\"value\":\"/entitydata @e[type\u003dItem,r\u003d10,c\u003d1] {Item:{Count:1b,tag:{display:{Lore:[\\"古の魂が刻み込まれている\\"]},ench:[{id:16,lvl:15}]}}}\"},\"text\":\"\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\"}",Text2:"{\"bold\":true,\"color\":\"white\",\"clickEvent\":{\"action\":\"run_command\",\"value\":\"/execute @e[type\u003dItem,r\u003d10,c\u003d1] ~ ~ ~ /particle iconcrack_88 ~ ~0.6 ~ 0 0 0 0.15 100\"},\"translate\":\"\u003d%1$s\u003d\",\"with\":[{\"strikethrough\":true,\"color\":\"dark_gray\",\"text\":\"-古の魂-\"}]}",Text3:"{\"bold\":true,\"color\":\"white\",\"clickEvent\":{\"action\":\"run_command\",\"value\":\"/execute @e[type\u003dItem,r\u003d10,c\u003d1] ~ ~ ~ /playsound mob.horse.skeleton.death @a ~ ~ ~ 1 1.2 0\"},\"text\":\"\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\"}",Text4:"{\"clickEvent\":{\"action\":\"run_command\",\"value\":\"/setblock ~ ~ ~ air\"},\"text\":\"\"}"}