He has rally die stating when he uses blades he can use the rally due to do 5 wounds. If he has flurry and blades does that mean he can do ten wounds a turn?

RALLY (5): Opposing Attack Rolls. When Sabretooth uses Blades/Claws/Fangs, before rolling the d6 you may instead remove his RALLY die to use it as the result.

Always a good idea to add the power or trait in question. There isn't a once per turn stipulation. If you have at least 2 rally dice, you can remove a die for each instance of blades/claws/fangs to make each a 5.

He would have to hit twice AND have 2 rally dice on his card to do the 10 damage.