The battle between Oliver (Stephen Amell) and Adrian Chase (Josh Segarra) culminates in a final epic battle on Lian Yu.
However, Chase has his own army – Black Siren (guest star Katie Cassidy), Evelyn Sharp (guest star Madison McLaughlin) and Talia al Ghul (guest star Lexa Doig) — and the forces collide in an explosive season finale.
After recent events, Oliver decides to recruit a group of unlikely allies — Slade (guest star Manu Bennett), Nyssa (guest star Katrina Law), Merlyn (John Barrowman) and Digger Harkness (guest star Nick E. Tarabay) — to defeat Chase.
Jury’s out on who might survive such an intense battle, though at least some of the above stars have booked permanent returns for Season 6, while others swear-off the Arrow-verse entirely.