Jesus. All the texts (App-94.) read "He".
I will. I am willing. See App-102.
his leprosy was cleansed. Figure of speech Hypallage (App-6). he was cleansed of his leprosy. Kaharizo is found in the Papyri and in Inscriptions in this sense.
Related Commentaries of Matthew 8:3
Matthew 8:3
3 And Jesus put forth his hand, and touched him, saying,I will; be thou clean. And immediately his leprosy was cleansed.