Forsyth is the green half of the typical red/green duo archetype found in most Fire Emblem games. The rest is a quote from the Fire Emblem Wiki.

"With a straight forward attitude and very passionate about fighting in the Deliverance, Forsyth sees Clive as his role model as a knight and he likes to imitate his grandiose and uncommoner-like speech. However, before his friends, he’s a simple man from a humble town. Despite sometimes resenting his childhood friend Python’s wishy-washy nature and not being able to understand his apathy, the two of them were reliable comrades on the battlefield."

Forsyth's english voice is Chris Cason. https://youtu.be/4tr3F08iwv0?t=1339