Arrow

Marc Guggenheim post this pic of the table read for the 100th Ep, now if you look on the right of the pic below next to Stephen Amell it's the actor that plays Robert Queen, Guggenheim post on the pic no flashpoint or flashbacks which clearly means his from Earth-2 and we all know who he was on Earth-2 "The Hood".

Ep 2 "The Recruits" synopsis:

SUIT UP — Oliver’s (Stephen Amell) new recruits for Team Arrow are Curtis (Echo Kellum), Wild Dog (guest star Rick Gonzalez) and Evelyn Sharp (guest star Madison McLaughlin). Unfortunately, the Green Arrow’s training methods prove to be too much for some of them to handle. Meanwhile, in the flashbacks, Oliver’s initiation into the Bratva continues.

Rumour is that Katie Cassidy will be appearing in the 100th Ep the only question is which version of Laurel.

My guess is Black Siren, the Earth-2 doppleganger of Laurel Lance since the people behind arrow have said the Earth-1 Laurel is staying dead

They haven't which one it is yet even if it is the earth 1 version doesn't mean she has to stay alive, one I do know is that the 100 Ep is part of the four way cross over it starts in Supergirl but it doesn't play a major part of the storyline.

Meet The Team Trailer

https://youtu.be/dMlYPnHYiK4

Stephen Amell has teased the return of Deathstroke for the 100th Ep.

"Break The Rules" Trailer

https://youtu.be/SYS22RtSVXY

Stephen Amell post up this pic and himself as Green Arrow with Supergirl.

The villian's that will be in the 4 show cross over will be race of aliens called The Dominators they were last seen in the comics in 1980's when there was a DC Comics cross over involving them.

http://www.ksitetv.com/supergirl/years-c...on/123625/