Few years back I remember doing the cresselia quest. I dont remember if I caught it or not nor can I start the quest right now. I am not sure what I can do? 

Hello @Seraphlost!

 

Hope you doing alright! 

 

I will gladly help you with information, from our variable it look you are at the part of where the NPCs hid themselves accordingly after defeating Sableye and need to wake up 4 pokemons.

 

To be able to proceed into this quest, 

You will need to wake them up by interacting with them while having a Pokémon with the move Uproar or Wake-Up Slap in your party.

 

You can found more informations about the quest there !

 

Hope it answer your question, dont hesitate if you have any further question!

 

I wish you a Good Luck for your quest and a wonderful day!

 

Very Respectfully,

 

Zarachi 

understood thank you have a great day