Sceptile has no real purpose as a lead. Gengar walls it out. Modest Tran? Go Naive, as lead, and holding Shuca Berry.
Adamant Hippo and no curse? Wtf. Replace adamant with Impish and use this 252 HP / 52 Atk / 32 Def / 172 SpD
with moves
~ Curse
~ Slack Off
~ Earthquake
~ Ice Fang / Stone Edge
Use Leftovers too.
Run Adamant on Gyara.
Other than that I don't have anything else to say. Offensive team though.