Someone cast Sphere of Force on W4 earlier, so it is pretty hard to attack in close combat.
Valorous doubles the damage, right? If so: Each point of power attack gives 3 damage, your damage is tripled.
So if you deal 2d6+10 damage, and power attack for 5, you would deal, (2d6+25)*3=6d6+75 damage.
And leap attack gives you x3 instead of x2 on Power attack damage, right?
So formula for calculating your damage is: Damage=(Base Damage + 3*Power attack value)*3
That's at least the way I read it. Since damage is abstract, and the way multipliers work with abstract numbers is described to add the multipliers together and deduct one.