Poisonnous

Ok thank you, very much for the help, i will try to beat him !

Hello, I was doing the halloween mission and I was in the nightmare part of Darkrai, my pokes died, and I went back to the beginning so instead of going left I went to the right and left the map, I was told that I have to defeat Horon, the thief of souls without any pokemon dying, the problem is that he is very strong, is there any way to do the mission again without having to defeat the boss? And that I really wanted to catch Dakrai