Need helpe bad! (Holon's cast form/ Magneton

[xHighTension]

I know this question might seem simple.

When I attach a multi energy or holon's castform to (for an example) "raichu", He does 100 damage and it says to discard all :lightning energies. Therefore, do I have to discard Holon's castform or multi energy?

 

[PokePop]

Yes you do.
If they provide L, they count as an L card.
Note that you don't get to choose what colors they provide