Hacking question

That you can recruit him you can, however there are some things you've got to take into account.

When you go into the airship, Umaro won't be there even though he JOINED the party. That's where you need to figure what event bits to activate and deactivate, and Madsiur has been more than kind to point some of those to you. When a member joins, some bits are activated in order for them to appear on the airship and stay there. Since umaro wasn't intended to join in the WOB, you would need to create a custom NPC and create custom event code to have him appear in the blackjack after he joins.

Another problem you might run into is if you go to any event and the code is not prepared to handle umaro. Your game will crash in so many unexpected ways you'll go crazy about it.

Hope that helps