Has anyone done the challenge quest with Medea Lily?

Can't say that I've tried her on this chellenge yet, but I imagine that it would be too difficult to pull off unless paired up with Mash or Waver. As for CE, for the Dante challenge I would suggest equipping her with ones catered towards NP Gain or Defense. Magical Girl of Sapphire puts her at a good start and can save her a turn to use her NP gauge filling skill right after her first Pain Breaker. And the more times she can fill up her NP, the more times she can provide a consistent Arts chain combo with other servants. "Holy Shroud of Magdalene" would be a pretty effective CE for her too since every battle has at least one Male servant to fight, and an extra 20-30% defense against Males might actually come in handy this time around. Overall, she's a servant more geared toward enemies that wreck teams using debuffs and poisons, so even though she can heal, she won't be effective for long without a shielder to back up her longevity.

If you want to further experiment with her on this, I can provide you with my own M-Lily to try out. I managed to get her to NP5 ever since the Prisma Codes event, so she can heal a good 6000hp at a time.

friend ID: 398,177,576

I ran her for pure heals but Irisviel probably would have been a better choice, looking back. Medea Lily is more valuable for her debuff cleanse, which is not really needed for this.

My comp was Gilgamesh, Hans, Support Merlin, Nightingale, Medea Lily, and Mashu. I still ended up needing to use command spells but yeah, I did it.

I used her bedause she was very useful in nerofest. Sadly what ended up happening was the enemies kept ganging up on her so i had to keep using heals to keep her alive until she eventually died, david ended up putting in more work

I used gil, medea lily, david, musashi, support merlin and mash