Green’s Dictionary of Slang

rizz n.3

charisma, charm, thus attrib.

[UK]Guardian 26 June 🌐 Baby Gronk shared that he would be focusing [on] his love for video games. To be fair, the purported ‘rizz king’ of the pre-pubescent sports world is probably not the one who actually said any of the above.
Dly Mail (London) 18 July 🌐 [US speaker] On Monday, Hill posted a TikTok using a filter which rated her ‘rizz level’, with it giving her 96/100 and ‘rizz god’ status.
https://www.polygon.com 19 Oct. 🌐 The word ‘rizz’ is a shortened version of ‘charisma.’ A person who has ‘rizz’ is endearing and good at charming their crushes.

In derivatives

rizzler (n.)

one who pursues the opposite sex, a flirt.

[Aus]Sydney Morn. Herald 18 Nov. 🌐 A rizzler, they agree, is someone who is flirtatious, someone older generations might call a pick-up artist.