What if the spell misfires and you get hit by it, not as bad but enough to hurt you a little and brings tears to your heart? Sorry dude... Never even as a joke talk that bad about someone who has shared everything with you honestly, until you both called it enough.
If she is allegedly spreading lies, then it is not necessary for you to reciprocate in the same manner, IMO. Try spreading good things, even just in mind, and see what happens, for a change.
Easy to say when you've been good and said nothing, and she's taken the opportunity to tell all and sundry a load of lies about you.
For example, I knew she'd try to paint herself the victim after I threw her out, so I told her if she spread a load of lies about me as she has before, which could destroy my life and lose me my kids, then I'd be forced to clear my name by revealing the truth.
She apparently felt so "threatened" by that, that she's "needed" to ring a "domestic abuse hotline" (this is a clearly vindictive and manipulative tactic as you'll see in a minute), and talk to her cousin, a social worker, who is an obnoxious cow who seems to adore my soon to be ex-wife, and who has consequently always hated me and said all manner of horrible things about me.
So now she's going around claiming she left me, and she had to blah blah blah, she's had to talk to a domestic abuse hotline, blah blah blah, and a social worker too.
She gives them a snippet of truth (whilst in tears of course), wrapped up in a load of lies, and people hear that, put 2 & 2 together, and come up with 999 which is a total pack of lies.
She once accused me of gaslighting - which is exactly what she's been doing all along.
I fucking hate her.
Plus she works on the railway, so it shouldn't be too hard for her to fall under a train.