Abyssoldier Guardian passive

I have been using it and notice that his passive is not working (the bond: auto protect plus), i don’t have any other abyssoldier, but even so guardian has never blocked any attack

bond requires another abyssoldier as far as I know.

Like @Zardecil said, Bond skill requires other Abyssoldier to work.
Please let us know if the skill description is not very clear in the language you are using.