"Increase damage to 2[W] + Dexterity modifier and riposte to 2[W] + Strength modifier at 21st level."
"1[W] + Dexterity modifier damage. If the target attacks you before the start of your next turn, you make your riposte against the target as an immediate interrupt: a Strength vs. AC attack that deals 1[W] + Strength modifier damage.