I tried creating a hero reviving type trigger. The hero has the Campaign Valerian hero death preventation behavior so when it takes fatal damage it gets the
incapacitated behavior which makes it invulnerable..
I'm trying to detect if the unit has that behavior and it doesn't work. I tried it with the death preventation behavior and it works, so im guessing it's a bug or something.
You don't need any behaviors to create a revive system.
To make a unit revive-able, open then unit in the data editor and set Death Time to -1. This makes it so a unit remains in the game even while it is dead, and allows you to use the inbuilt Revive Unit action on it. You'll want to save the unit your going to revive to a variable for simplicity I imagine.
If you're using a unit you made yourself, you'll also want to check Revive Type in the data editor and make sure it is set to your custom unit.