To begin your bond with Basilio, the final party member in Metaphor: ReFantazio, you need to follow these steps:

1. Complete the Main Story: Ensure you have progressed through the main storyline to the point where Basilio joins the party. This typically occurs after defeating Louis at the Altabury Opera House.

2. Travel with Basilio: Once Basilio is in your party, you need to travel with him on the Gauntlet Runner. This is a crucial step to initiate his bond.

3. Speak to Basilio: After traveling with Basilio, speak to him in the engine room corridor of the Gauntlet Runner. This action will start his bond.

4. Progress Bonds: Basilio’s bond will automatically increase as you progress through his events. You will need to meet specific requirements for each rank:
– Rank 2: No additional requirements.
– Rank 3: Speak to Basilio while on a trip in the Gauntlet Runner.
– Rank 4: No additional requirements.
– Rank 5: No additional requirements.
– Rank 6: Reach Imagination Rank 5, then speak to Basilio.
– Rank 7: No additional requirements.
– Rank 8: Speak to Basilio with Eloquence Rank 5, then complete the side quest “A Brother’s Mercy.”

By following these steps, you can initiate and progress your bond with Basilio, unlocking his full potential as a party member in Metaphor: ReFantazio.