Mesaana - When Mesaana is about to do Egwene in she'll be whacked on the head by Laras's cudgel. Or backstabbed by Nicola.

Cyndane - Rand is about to breathe his last breath but Cyndane can't bear to let Lews Therin go. She draws on the source to try to heal him and Alivia wipes her out, thinking Cyndane is about to do something nasty to him - thereby helping Rand die in the process.

Moghedien - will leap out of the shadows to duel Nynaeve and Cadsuane will swat her like a fly.

Demandred - Mat, in a parallel of the way he killed Couladin, who was also focused on destroying Rand.

Aran'gar - The Seanchan are too powerful a force for order for the shadow to completely ignore. With all the damane around, someone who channels Saidin may be seen as having a better chance to influence or kill the new empress. This will lead to a battle of bosoms, as Fortuona's secret bodyguard, Selucia, gives her life to do her duty.

A Shadar Haran/Padan Fain double knockout also has its parallels in the opposing forces cancelling each other out, so I'll plump for that too.

Slayer - Perrin seems the only likely choice here, which probably means it's someone else entirely. My guesses would be Faile or Hopper.