Before the Big Bang (Megumin) (Patreon)

Megumin gets off on charging one up. 

Oh and just in case you don't know who this character is, she's from the show Konosuba. She's a wizard who really loves blowing stuff up with her powerful attack magic... but it takes time to charge up those spells! So here she is getting off before releasing a particularly big explosion! The poor fool who has to suffer the consequences...