Persona fusion discussion
The protagonist's arcana is The Fool. It's mostly numbered as 0. At first, The Fool (or Jester) is an innocent, inexperienced person that doesn't know what to do with his life. His perspective on life is still a raw one. The Fool can communicate with anyone because of his naivety, and earn experience. So, it has the capability to change to anything and that's why it's suitable for the protagonist.
"The Fool Arcana does not mean that it can be taken lightly. The Fool is number zero. It is the void from which all other things begin."