These items will help you pass the Dual DC 25 checks for any character for Religion and Arcana
1. Shapeshifter Boon ring + disguise kit/Disguise Self + 1d4 bonus
2. Warped Headband of Intellect - sets Into to 17 so +3 Int checks.
3. Cast Fox's Cunning - Advantage on Int checks (warning Concentration) (You can upcast this on more than one companion)
4. On a separate character use the necklace of Guidance to Caste Guidance + 1d4 to checks. (Concentration based)
5. Mage's Friend +1 to Arcana and Religion
Obviously there are other options like Bardic Inspiration, and the Nymph Bonus but can people think of anything else that would help?
Basically every one of your party can get the +2 and then remove the -2 with Remove Curse.