He's the one Kage who should be spared for the future. Gaara comes from the same generation as Sasuke, he has no reason to kill him for the same reasons as wanting to execute the others. So either Naruto saves him or Sasuke decides to spare Gaara. 4 outta 5 Kages are still unaccounted for so we can't say if Sasuke succeeds or not. But Gaara should live regardless so it works out for me.