You have a pretty cool team, but it seems a bit weak to Nasty Plot Celebi, as it can easily set up on Lilligant and even Starmie if it's at full health, and at +2, it can KO every member in your team. The easiest way to fix this would be using Hidden Power Fire on Lilligant, which can not only Revenge Kill Celebi but it simply prevents it from setting up, Hidden Power Fire also makes sure Lucario can't set up on Lilligant and wreck your team.
Your team is also slightly weak to Terrakion (and other Fighting types like Keldeo in general) as your main way to deal with Fighting types (Dragonite) can't take common attacks like Stone Edge from Terrakion or a Keldeo's Hidden Power Ice, while Starmie is too frail to be able to switch on powerful attacks and it can't do jack due to the lack of a stab move. Something you could try is using a 248 HP / 32 SpA / 228 Spe EV Spread on Starmie, while using Psyshock over Hidden Power Fire, as this will allow Starmie to switch on Terrakion and Keldeo and defeat them.
Hope I helped.