Board Thread:Questions and Answers/@comment-203.63.233.167-20180111110700/@comment-27104094-20180111171256

I don't think you can invest after ardford. For better results you need the 3 merc companies. If Megail RP is high enough (talking to her first at the reunion is a good idea depending of your game) owning the Yhilin Bank is a good idea.

Saving Aka first in Chapter 1 (yes it's very early) is a good idea for Yhilin battle

You will need 1,000,000 proN to Merchant Guild Membership.

Ownership of Yhilin Bank is needed for bank profits in Chapter 4.

You can own the premium steel after the war and even at Chapter 4. Having Robin's Crystal isn't needed for best results in 3AW.