>>57890045I did it with
2/5 EXR A Lillie
3/5 EXR V Elio
3/5 EXR U Elio
Spam her ghost attack on Raichu and debuff with Elio, the other U Elio gives bes, circles and buffs, it could take some attempts because of paralysis and flinch added effects from Hau's side but it was doable in the end.
>1st sync U Elio>2nd sync V Elio >3rd 4th A LillieElio can also save some health for you with his confusion, plus he also debuffs -2 Attack and can buff his own bulk later once you make sure the enemies are at least at +0 Sp.Def, and Morning Sun for the late game. If sidemons somehow remain alive focus on nerfing Dhelmise because it spams Surf later, Elio debuffs Attack so it is better to take care of it. Also you can steal an extra turn taking out Dhelmise before finishing Raichu with the remaining 2-3 turns before it syncs.
U Elio might faint to Volt Tackle but in general U Elio's TM has a good refresh rate and adds extra Regen to keep Lillie's damage filter active for when it is required.