In Assassin's Creed II, which Renaissance inventor becomes one of Ezio's closest allies?

In Assassin's Creed II, Renaissance inventor Leonardo da Vinci becomes one of Ezio's closest allies.

Leonardo helps Ezio interpret Codex pages and creates or adapts equipment that supports the Assassin's missions. Their friendship begins in Florence and continues as Ezio travels through Renaissance Italy, with Leonardo later working in cities including Venice.

The real Leonardo da Vinci was a painter, engineer, scientist, and inventor whose surviving notebooks contain studies of anatomy, mechanics, and flight. The game uses his historical reputation while placing him inside its fictional conspiracy narrative.

Michelangelo and Raphael were also major Renaissance artists, but neither fills Leonardo's role as Ezio's recurring inventor and technical adviser. Galileo lived later and is not Ezio's principal ally in Assassin's Creed II.