I'll solo Charybdis for you for 1 million gil. Based on the following conditions though:
1) 500k up front when we start camping, and the remaining 500k upon a successful kill before you cast lot on the drop. If we don't get claim I'll keep helping you until we do, but you're not getting that first 500k back once I've been hired and invested time in this.
2) You obtain the time of death (you'll need a Gold Beastcoin and some form of Sneak to reach camp). If you absolutely can't do this on your own, I'll get ToD for an extra 100k.
3) You help claim the mob in case of competition. I'll try to help with claim, but as RDM/NIN I don't think Dia is going to beat someone else with Provoke considering how small the spawn area is.
4) I'm not responsible if you cast lots but have 80/80 inventory and end up losing the drop. I'm also not responsible for helping you navigate Sea Serpent's Grotto or providing you with Sneak.
5) (OPTIONAL) If you can kill the other Devil Manta that spawns in Charby's room during the fight itself, that'd be helpful. If not, I'll bring someone else to do it. No biggie either way. The fight itself takes me about an hour and 20 minutes.