Chris has no empathy. I'd show him none in return.
First order of business: Arrange for Barb to be involuntarily committed to a nursing home or mental hospital... if all else fails call 911 and tell them she's committing suicide, anything that will force a psychiatric evaluation. Once she's disposed of, I'd round up all of Chris's toys and vidya... arrange to have it all donated to Child's Play and Toys for Tots. I'd break open the file cabinets to leak more Chris dox... original Autism papers, high school transcripts, photos, etc to the internet for all to see. I would then proceed to blow Chris's tugboat on jars upon jars of pickles, which I would proceed to record myself eating. I'd then record myself excavating Patti's grave yelling JULAY. Finally, I'd blow the last of Chris's tugboat calling up some melanin-enriched male prostitutes to engage in a circlejerk orgy around Patti's corpse, precisely timed so Chris and I would switch back in mid-orgasm. This whole ordeal would be streamed on the internet, of course.
Of course, he'd probably screw up my life just as badly in the space of a day.