Predator lets you reroll 1 red die, 2 if the defender's PS is below 3.
Dengar lets you reroll 1red die, 2 if the defender is a unique pilot.
Both cost 3 points.
Is it worth 6 points to be able to reroll up to 3 dice per attack on everything but higher PS generics? You'd get to reroll 2 against them. It's kind of overkill but you'd be able to reroll 4 dice on uniques that get Muxed.
