/scoreboard objectives add al dummy
/scoreboard players set @p al 1
/summon ArmorStand ~ ~ ~ {CustomName:"al1",CustomNameVisible:1,Invisible:1,Invulnerable:1,Tags:["al"]}
/summon ArmorStand ~ ~ ~ {CustomName:"al2",CustomNameVisible:1,Invisible:1,Invulnerable:1,Tags:["al"]}
...
/summon ArmorStand ~ ~ ~ {CustomName:"al8",CustomNameVisible:1,Invisible:1,Invulnerable:1,Tags:["al"]}
/tp @e[tag=al] @p[score_al_min=1]
/execute @p[score_al_min=1] ~ ~ ~ /tp @e[name=al1] ~1 ~ ~
/execute @p[score_al_min=1] ~ ~ ~ /tp @e[name=al2] ~1 ~ ~1
...(faire ça pour chaque direction)
/execute @p[score_al_min=1] ~ ~ ~ /tp @e[name=al8] ~1 ~ ~-1
/testfor @p[score_al_min=1] {SelectedItem:{id:minecraft:diamond_sword,tag:{display:{Name:"Lightning Master"}}}}
(en conditionnel) /execute @e[tag=al] ~ ~ ~ /summon LightningBolt
(Pour arrêter) /scoreboard players set @p al 0
/kill @e[tag=al]
Un autre défi ?