Imho, the most useful abilities of Ruby Droplet is: Absorb, Bubble and Blood Drain. Only Absorb scales with power, and a very miniscule amount. So not really useful for it.
Some people advocate the H/S breed due to sometimes being able to bubble before a big hit comes. But imo the problem with that is that bubble have a meaty 8 round cd and you wont be able to use it as a reliable counter.
I believe H/H is the way to go. As it gives you a higher max health. And when you combine it with Sunlight weather, its tanking ability simply goes through the roof! At this point, a sunlight buffed Blood Drain restores nearly 1000hp per cast. Easilly allowing you to fill up to your sunlight empowered max health. A true health tank, while steadilly eroding the opponent with Absorb and Blood Drain.