I was out hunting for a Pianus card earlier on a whim, and I actually found one. Not only did I find one, I found three. Along with the cards that dropped (Guild mates took the other two), three miniature Pianus statues appeared in the loot.
I have them sitting in my inventory right now, and I'm while I know I'm supposed to use them to get Hero's Will, I'm not sure what precisely is entailed in that process. From what I DO know, I take the statues to Carla, and she lets me into a room with Sharks and Bone Fish. I kill them, gather fragments, and then am awarded a skill book. Use that skill book, and you have unlocked Hero's Will. I think you do something will the certificates (Zakum, Pap, Pianus) in order to raise the maximum skill level.
I still have a couple of questions here, though.
1. Can I bring a party of people in? I don't see the point in everyone buying their own statues if you can.
2. Can someone confirm and explain what the certificates do?
3. How many of these will I actually need? If we can do this as a party, can we get a few people through with 3 statues?
4. If it's only useful for Horntail and Chaos Zakum, should I really bother? I'm mega weak and I'm not going to be going on either of those runs any time soon.