A couple comments with regards to healing your vampiric dragons:
(1) In the base deck, the only creature you have is the dragons, so they will always be the top priority for CC.
(2) In the event of an opponent without CC, where poison from liquid shadow is the only damage your dragon takes, a single dragon will kill the opponent at the same time it dies itself, so you don't need to worry about healing the dragon.
(3) In the event of an opponent with CC, they would still need to use 2-3 cards per dragon, and the number of cards per dragon they would have to use would not change from the poison your dragon is taking until your dragon had managed to do a lot of damage.
(4) With a small number of notable exceptions, most of the decks you'll face aren't going to be heavy enough on CC to be realistically able to take out more than one dragon.
(5) Adding an additional element for healing severely unbalances your quanta. It isn't always a bad thing to add an element and cope with much more unbalanced quanta, but it isn't a great idea when you're adding an element to take care of a problem that can already be handled in-element.
(6) The +3 hp from blessing adds a card to the number of CC cards required to kill your dragons at high hp, and also can reduce the number of turns you need to hit your opponent with your dragon(s) before winning.
(7) Like I said before, while I still don't think you really need to worry about healing in most cases (in that I believe that the losses to speed/stability you'll suffer in situations where healing won't be useful will be greater than the gains to stability/survivability you'll receive in situations where healing is useful), 1-2 holy lights can mitigate 2-3 CC cards worth of damage apiece, and also won't be dead cards in the (frequent) situations where healing your 10-base-hp creatures isn't actually necessary, since they can be used to heal you.
(8) If you want another way to consider the healing aspect, think about this: Not very many creature decks use creature healing cards. Your base creature has 10 hp, which puts it as one of the highest base-hp creatures in the game. Your dragon would have to attack a minimum of five times (for 50 damage to the opponent and 50 healing to you) before it would reach the 5 hp that a lot of the unupped dragons have, which is still an amount of hp that's widely considered to be mostly out of CC range, since it can still only be taken out by lightning or high-quanta bolts. Lightning isn't really a huge issue for the most part because if you're against aether you're going to just flat-out lose to dim shield (as you have no PC/momentum/etc), and bolts aren't really a huge issue because if you're against a fire stall, you're also going to probably just flat-out lose (as they are sufficiently packed with CC that healing isn't ever going to be an issue).
TL;DR: I still say don't add water just for purify. If you want creature healing (which you don't really need), stay in-element and use blessing, holy light, or guardian angel (in that order of my personal preference). Staying in-element will give you much better draws overall due to having a much lower chance of failing to draw the appropriate quanta.
