Sea Dragon Bonus - Boss Armor

[TheNoid]

So I messed up and forgot to bring my Necromancer into the Sea Dragon bonus stage, but made it to the end with only the boss left. I have 3 gold chests and don't want to give up, but I am afraid I am just wasting coins at this point. Does anyone know what I need to hit the boss with in order to kill it? My lineup is:

6* Medusa The Jealous - Level 40
6* Succubus Queen - Level 26 or 28
5* Gigas The Saboteur - Level 35

None of their individual attacks are enough to kill it. Also, I have no one to half the armor.

I figured if I lit up the reels with almost completely one color it might be enough to kill it, but not sure.

Thoughts?

[Nakazawa]

Defense is 53k. No demon atk x2 cards, avoid defense skills or poison means quit, sorry. I had this too once

[TheNoid]

Thanks 60000 coins committed and glad to get the confirmation even though it's painful