Detect lightning strikes

Solution 1:

We cannot select LightningBolt in a target selector so we cannot detect all mobs around a lightning bolt. Instead we can detect all mobs that have a lightning bolt around them.

Setup:

/scoreboard objectives add Selector dummy
/scoreboard objectives add Initiated dummy
/scoreboard objectives add Marker dummy
/scoreboard objectives add Charged dummy
/scoreboard objectives add Change dummy
/scoreboard objectives add Kill dummy

Clock:

/scoreboard players set <Select Original Mob> Selector 1
/execute @e[score_Selector_min=1,score_Initiated=0] ~ ~ ~ summon Creeper ~ ~ ~ {CustomName:Marker,CustomNameVisible:0,Invulnerable:1,NoAI:1,Silent:1,PersistenceRequired:1}
/scoreboard players set @e[type=Creeper] Marker 1 {CustomName:Marker,CustomNameVisible:0,Invulnerable:1,NoAI:1,Silent:1,PersistenceRequired:1}
/scoreboard players set @e[score_Selector_min=1,score_Initiated=0] Initiated 1
/execute @e[score_Selector_min=1,score_Initiated=1] ~ ~ ~ tp @e[type=Creeper,r=1,c=1,score_Marker_min=1] @e[score_Selector_min=1,score_Initiate=1,r=0,c=1]
/scoreboard players set @e[type=Creeper,score_Marker_min=1] Charged 1 {CustomName:Marker,CustomNameVisible:0,Invulnerable:1,NoAI:1,Silent:1,PersistenceRequired:1,powered:1}
/execute @e[type=Creeper,score_Charged_min=1] ~ ~ ~ scoreboard players set @e[score_Selector_min=1,score_Initiate=1,r=1,c=1] Change 1
/scoreboard players set @e[type=Creeper,score_Marker_min=1] Kill 1
/execute @e[type=Creeper,score_Marker_min=1] ~ ~ ~ execute @e[score_Selector_min=1,score_Initiate=1,r=0] ~ ~ ~ scoreboard players set @e[type=Creeper,score_Marker_min=1] Kill 0
/tp @e[type=Creeper,score_Marker_min=1,score_Kill_min=1] ~ ~-600 ~
/scoreboard players set @e[score_Selector_min=1,score_Initiate=1] Initiate 0
/execute @e[score_Selector_min=1,score_Initiate=0] ~ ~ ~ execute @e[type=Creeper,r=1,c=1,score_Marker_min=1] ~ ~ ~ scoreboard players set @e[score_Selector_min=1,score_Initiate=0,r=0,c=1] Initiate 1
<Run command on entities with Change score of 1>

1. Original Mobs Selected
2. Creeper summoned on non-Initiated Selected mobs
3. Mark the summoned Creeper
4. Set the non-Initiated mobs to Initiated
5. Tp the Creeper to the corresponding mob
6. Mark Charged Creepers
7. Mark Mobs that are selected, initiated, and have a charged creeper near them
8. Reset kill score for all creepers
9. Set kill score of all creepers that have a valid mob near them to 0
10. Discard the remaining Creepers
11. Reset Initiate score
12. Set Initiate Score of all valid mobs that have a valid creeper near them to 1
13. Run your command on the mobs marked with Change to swap the mobs.