bucc/Striker with SE

SE works for buccs and strikers the same way it does for every other class, it adds a % to your damage, say SE adds 60% damage, a buccaneer (if they crit) would do the skills damage+140% of the skills damage (because stun mastery does 140%)+ an extra 60% on top of that 140 for 200%. So they'd 200% aka double what they'd normally do.

Buccaneers get 140% + 160%
Strikers get 140% + 100%

Flash Fist would be 270% + 140% + 100% = 510% for Strikers and 270% + 140% + 160% = 570% for Buccaneers.