Stabbing Dracula in the heart with a stake is the traditional violent method for killing vampires. Trying to fight them when they are awake is generally suicide...
If you play apple 2 version Dracula dies in an extra violent sounding way, giving out a horrible scream!
efeats Fire (Destroyer of Life)
Depends on what legends you go with. Fire can often represent life. In reality fire is needed to allow some plants such as the redwoods to sprout and grow anew. The cones require heat to seed!
Likewise, water can be a destroyer of life... Water can cause people to drown, it is highly destructive, causes floods, etc.
But fire and water are usually the contrasting elements, in the myths.
IIRC, KQ7 has elements of the 'fire = life'/water=life" motif though. The sun's fire and water both shared on the same god!
And I really, really doubt that Graham is weak. Look at his muscles in KQ5 alone--the man is built like a beast. I think KQ1 saying he was too weak to fight the monsters was more of a technical/budget limitation than anything else.
It's also storyline based. Consider in KQ5, Graham can also be 'too weak' to move the boat, thus requiring a magic spell! It also says he isn't strong enough to defeat the witch in KQ5 as well (try defeating the witch through other methods/hand, etc). She is too well protected either by magic, or the fact she isn't entirely human! The same is said if you try to do anything with the Yeti as well, "graham is too weak to fight it"... I believe it also says something similar if you attempt to 'attack' the bandits, wolves, harpies, the blue beast, dink, or Mordack as well. Thus in each of these cases Graham had to find alternative method using his brain to overcome the monsters!
"having strength" though doesn't mean you are skilled or strong enough to fight an ogre considering that an Ogre is stronger than a human, with much larger muscles (exactly as the game describes, "ogres are practically indestructible"(KQ1AGI)). Wolves are tough for even the strongest fighters to fight, because they can latch on and don't let go, and have high agility (again something the game describes). If you lose enough blood, you die. The sorcerer has the magic spell protecting it, as does the leprechauns (again preventing Graham from being able to defeat them, and force them out of Daventry). Even the game suggests that the witch is much stronger than she looks, Graham was only able to defeat her, since he caught her off balance! Trolls are generally stronger than humans as well! There is even a reasonable explanation for the dwarf as well, IIRC. "He is too quick for Graham to catch!" (KQ1AGI)
The game reinforces these traits of the monsters if you somehow get caught by them, leading to the various death scenes, paralysis, or being robbed. The only way to avoid many of these attacks is to have the magic shield or fairy spell.
BTW, the KQC also discusses these physical traits of the various races!
Interesting enough the novel Kingdom of Sorrow also suggests that Graham isn't the most skilled as far as sword fighting, and isn't that strong. But that he makes up for it in wisdom.