Summon Shadow: Every third level gained after 9th adds +2 HD (and the requisite base attace and base save bonus increases) to the shadowdancer's shadow companion.
Shadow Jump: The total distance of a shadowdancer's shadow jump doubles every two levels after 10th.
Bonus Feats: The epic shadowdancer gains a bonus feat (selected from the list of epic shadowdancer feats) every three levels after 10th.
Epic Shadowdancer Bonus Feat List: Blinding Speed, Dexterous Fortitude, Dexterous Will, Epic Dodge, Epic Skill Focus, Epic Speed, Exceptional Deflection, Improved Combat Reflexes, Improved Darkvision, Improved Whirlwind Attack, Infinite Deflection, Legendary Leaper, Reflect Arrows, Self-Concealment, Spellcasting Harrier, Superior Initiative.