Arslan Senki (TV): Dakkan no Yaiba retells the events of the series' first 13 episodes, summarizing the events that transpired from Arslan's escape with Daryun, to their time in the Peshawar Citadel.
Kaido is the best site to watch The Heroic Legend of Arslan
SUB online, or
you can even watch The Heroic Legend of Arslan
DUB in HD quality.
You can also find
anime on Kaido website.