How do I make the powerful weapon in Kingdom Hearts 2?,and where is all the stuff I need?

If Its Ultima weapon here is what u need from how much i can rember

orichim+-7 yes 7 oh synetheisis a s ranked thing ad get the shard that makes its rank be decreased par half then get the items u need and 7 orichim+'s and it should be avabile for u to synethiese it and its power lvl is 7 and fenir u get after u beat sephy