Arrow 6×20 “Shifting Allegiances” Season 6 Episode 20 Promo – RENE RETURNS TO NTA — Oliver (Stephen Amell) turns to an old friend to help battle Diaz (guest star Kirk Acevedo). Meanwhile, Rene (Rick Gonzalez) is out of the hospital but has a hard time re-adjusting to life as Wild Dog. Also, Lance (Paul Blackthorne) discovers something shocking about Black Siren (Katie Cassidy). Alexandra La Roche directed the episode written by Wendy Mericle & Rebecca Bellotto (#620). Original airdate 4/26/2018.