I HIGHLY recommend you doing "What Lies Below" Quest & killing Bork.
He is a fairly easy Runescape Boss, he gives 5K Slayer exp + 5 Blue charms + 7 Crim charms per kill.
Ps. You can only kill Bork once every 24 Hours.
(Quest has no Melee/Magic/Range/Hp/Prayer rewards)
It gives 2,000 Defence and 8,000 Runecrafting Exp. That is it.