It's the final arc of the drama so last ~10 eps or so though the signs were there fairly early on.
As for the question of whether he is good, that's open to interpretation depending on one's definition of justice/righteousness and its relation to motives for doing things. The friendship is strongest in the first ten episodes or so and then starts fracturing by the middle stretch of the drama.
playlist of individual episodes: https://youtube.com/playlist?list=PLQpbSI4YEdmofhPhPWfAJU0NpZO9q82YH
Youtube playlist: https://youtube.com/playlist?list=PLpNTjTrBrqfZyRuflNt3H9wJsObxmasx9
All the episodes combined: https://youtu.be/lUNwT1qgd8Q (Eng subbed)
As for the question of whether he is good, that's open to interpretation depending on one's definition of justice/righteousness and its relation to motives for doing things. The friendship is strongest in the first ten episodes or so and then starts fracturing by the middle stretch of the drama.