A trooper in the Seed Embryo state doesn’t count towards casualties. But Retreat isn’t based on casualties. It’s based on survivors. So how does Seed Embryo help? Thanks.
I think you mean Spawn Embryo. The full quote is: During the game, troopers in the Spawn-Embryo state do not count as casualties for the purposes of determining the total point cost of surviving troopers. Which makes it pretty clear that the rules consider anything not a casualty to be a survivor.
The quote for Retreat is... http://infinitythewiki.com/en/Retreat! "If the sum of the survivors' Cost in points is equal to or less than 25% of the points available for building the Army List, then that army enters a state of Retreat!" So troopers in Spawn Embryo state do count torward the total points of surviving troopers when calculating retreat. - - - - - Between Ikadrons being a staples and Spawn Embryo, it's unfortunately very hard to go in Retreat! as Shasvastii.
To make sure there is no confusion, Seed Embryo (which is a different skill and used on Seed Soldiers and Cadmus) also counts as being alive. It's just an alternate troop profile.