Jack in the Pulpit may be interesting. I don't know if it will be enough but it may works. Water Speedwell may be useful too but you will hit hard the Hit rate debuff limit (caped at -70%). Not a bad debuff though. May worth the RG.
All the good ATK debuff are pure 6* sadly. I think you won't find promoted 5* with more than -30% ATK.
You may need some healing too. Or even better, a third evade girl (+ intercept). Vanda is interesrting if you can put your hand on her.
Sadly, most of the old 5* are bad due to not being reworked to fit the new game style. Most of the evade 5* still have that poor 80% evade first two turns and then 50%.

If you could gives a list of your 6* and 5*, it may help. Sometimes, there are hidden gems. Meh girls that really shines in a very specific combinaison.