Another electric shuttle idea: have the damage they do vary based on how many targets it hits. Some sorta of 1/log scale is prob best.
Example: you hit <4 targets, you do full damage to them
<16 targets, you do 1/2 damage
<64 targets, you do 1/3 damage
<256 targets, you do 1/4 damage
<1024, 1/5th damage
<4096, 1/6th damage
Could have it reduce quicker/slower by changing the log base(currently using base 4).
edit: If you don't want to precompute the number of targets being hit, the first 4 targets could take full damage, then next 12: 1/2, etc.