I suggest you get your mage level up to 25 just incase you might have to teleport out of there =P. Also remember to bury your bones to get that prayer level up, just in case worst things come to worst and you end up dying, you can use Protect Item at... level 25 if I remember correctly. But yeah, I agree with tripsis, you should probably get your combat level to about 40, 45+ or so. I did Dragon Slayer at like... level 54 xD so I didn't have any trouble, but at a higher level than you are at the moment then Elvarg should go down without a big hissi fit.