Tips for making a Heroless deck.
Building a normal defense will not work. You need a defense that can hold the whole game against any offense(Including defenseless' onslaught of an offense). Also you may have to adapt your playing style to play Heroless.
Knowing your deck's weaknesses (through play testing) will also be needed, so you can build with them in mind and compensate for them with artifacts, fortresses, etc.
Holy grail is a very useful card to convert your evil characters with but it's not 100% entirely needed with the FOOF (faith of our fathers) card "Healing of naaman" which heals an evil character and converts it to a hero. Regardless of that I would still use Holy grail and at least one other convert. Using Lampstand of the Sanctuary with Tabernacle also protects against your precious Holy Grail being destroyed by a Dominant.
You need at least a few powerful good enhancements that can get through any defense at least twice. The less the better but don't cut yourself short. Also storehouse helps keep them safe since only cards I have seen that target storehouse are evil and you won't be rescuing till most of those good enhancements are in your hand anyways.
You do not need ONLY human heroes! Mix in demons to help your defensive strategy if you want. Just remember not to short yourself on humans to convert or you will most likely regret it.
Fortress and artifact cards are very helpful (especially to cover small holes in your defense) and using many of them in Heroless isn't that uncommon but remember not to be excessive with it. Artifacts are powerful but remember evil characters and enhancements are the key to a good Heroless.
I saved the most important rule with Heroless for last. Have fun with it! Be creative, Many people have asked me will a certain color make a good Heroless deck and truth is, I don't know. I haven't used them all but it never hurts to try something new and if you come up with a new Heroless strategy and email it to me with details I'll put it up on the site with credit to you!