If Silver Axe does have Urouge's Fruit, and survived God Valley (which fits, because we haven't seen him get the title Silver Axe yet)...
Any chance Urouge and Silver Axe knew each other, and Urouge ate his Fruit after he died?
Kyo is clearly Yakuza from Wano, like Shiki (watch the latest Tekking video if you don't believe me).
Urouge has the Retribution Fruit, and has some similarities to Yakuza: perhaps Enel killed Kyo in Birka, and Urouge wants revenge?