Fanon Technology

Time travel [semi-canon] – There was limited time travel both by magic and tech, would need a little refinement. He/She may be too young for you now, but visit the future (or have him/her come back) and it's suddenly legal.

Personality swap [semi-canon] – Mostly used to turn a good person to evil, or evil person to good. Minor adjustments and that person you lust after, but who hates your guts, will be begging for sex.

Growth ray [semi-canon] – it can make living creatures huge (Rufus and a poodle) and revert them back. Modified it could make a real penis enlarger for that small dick, or turn Kim's A-cup titties so huge she'd have trouble standing up.

Genetic splicer [canon] DNAmy's tool for combining creatures. Modify for sexual purposes? Give the human half of the splice the size, strength, and cock of a horse or bull?

Genetic re-sequencer [fanon] – Most often Kim, but sometimes Shego, or Bonnie, or Ann, turns futanari. I'm not a fan of the genre, but if you are this is the tech to use. Sometimes she can shrink it back into her body. In some stories she just tries to avoid anyone finding out – like that is really going to work in porn.

Gender swap [fanon] – Ron appears fairly often as Veronica/Rhonda. It is Ron in drag. (I'm not going to write any of those – but if it turns you on, go ahead.) In a few stories we have a Veronica/Rhonda really female. Produced by magic, fanon tech, or the Ron from a gender-swapped alternative universe getting into this one.