You’re missing [mod:shift,harm]
as the first condition.
#showtooltip
/cast [mod:shift,harm] [mod:shift,@targettarget,harm] [mod:shift,@targettargettarget,harm] [mod:shift,@focus,harm] [mod:shift,@focustarget,harm] [mod:shift] Flame Shock; [harm] [@targettarget,harm] [@targettargettarget,harm] [@focus,harm] [@focustarget] [] Lava Burst
I personally would drop all instances of @TargetTargetTarget
it’s a pretty niche use case.
Different approach if you’re interested.