Castion Fortify (Earth Shield 5) does not cancel Overload channels as do most defensive cooldowns, just like Burning Retreat cancels it.
Fortify does not cancel Stone Sheath either.
Actually, it’s the Fortify itself that needs to cancel anything channeled or casted. It’s pretty annoying to have to cancel Stone Sheath to be able to Fortify if said incoming attack is unblockable (Necro Wells, Revenants, etc.)
Alerie Despins