Vampires - you should be afraid of the night

[Dragar]

Very nice, the only major downsides those that Micah brought up. In particular it definitely needs to be part of a strategy employing strong dominion push. As a purely defensive strategy I think it is perhaps overkill

The other potential weakness is someone beelining to your capital, either overland or with magic. If I knew what I was up against I'd be planning a blitzkrieg to take out the enemy capital, at which stage all of the immortality is out the door. Seeing as the strat is largely defensive in nature an attacker can take his time getting it just right. I'm sure there are a number of ways you can make that difficult to do, if taking capitals was easy a large number of strats would fail, but this strategy in particular would unravel very quickly if that occurred.