Hammer - What if the lightning will struck straight forward reaching 20 blocks maximum and damaging all enemies that hit by lightning (2 hearts damage for the enemies that hit by lightning and 3 for all the enemies that is hit at the very end of lightning). Lightning is 3 blocks wide and 20 blocks long.
Too OP in my opinion. 3 blocks wide is crazy, especially when there are a lot of people. Also, it is much harder to code than a normal lightning strike.