Nullify, nullify, nullify. Bait Maeve into the open, then hit her with the good ol' Nullify beam. More often than not, her Nine Lives will still be on cooldown, and someone else is gonna be there to kill her.
The best way to get Torvald down is the combo between Wrecker and Street Justice. Keep your distance if you know Nullify is up, because Nullify is your ruin. Knock his health down from a distance, rush in, and pounce once hes at/below half health.