I gave giants high natural skills. A dragon quickly melted the giant; a bronze colossus was getting dents as well as digits (and nose) torn off until he chipped one of the giant's bones; a hydra and the aforementioned dragon killed each other, with the hydra ripping out the dragon's throat and causing it to bleed to death before melting; the battle between hydra and giant was about 10 seconds and one fast-healing bruise from being a
curb-stomp battle in the giant's favor; the battle vs. the roc was a definite CSB, although the giant got a cut; and a blood hulk made the giant cry Mommy. It's a pretty good spot to be, IMHO.
Oh, and blood hulks dropped in lava will have their blood boil away, several times after the blood in all of their body parts has been reported as "gone." This indicates that the blood regenerates.