This Comic's Storylines:

In all honesty, Sindra'a magic attack probably should have been stronger. That said, if it were too much stronger the heroes would have almost no chance of survival.
In my head, the heroes tend to sit around 1200HP or so. This means I tend to have them be able to suffer 10ish weaker hits, or about 4 really good attacks/spells. It's really in line with the old energy meters from Castlevania where the hero (Whathisname Belmont III) could sustain just about the same amount of hits before death (certainly better than the Ghost 'n' Goblins way of two hits and you're out).
Of course, as they level up they should be able to handle further damage, but I still, in my head, keep them somewhere arund where they are just for consistency.
Truly, since it's not as if I have these numbers written down in any "official" source, it's not as if I can't just make them up and reinvent them as I see fit.
 
    

When evil spreads across the land, and darkness rises and the monsters roam. When the creatures of the night make beautiful music, and the things that go bump in the night go bump with greater enthusiasm. When the world is in peril and is in need of a hero...

These guys are, sadly, the best the world can hope for. These are the adventures of the heroes of CVRPG. They mean well, they try hard, and occasionally they do the impossible...

They actually do something heroic.