(Runes aren't a common school of magic, as most of the art was lost with the end of the Giants, but there are some schools that preserve some of that ancient knowledge and have made great strides in recreating some of them. However, our great scholars still can't match the power of the Rune Carvers of the Goliath clans. Not only have they retained the true power of the craft, they've managed to translate their Rune Carving to Tattoo's that they bestow upon those who prove their worth.
Chista has the mark of the Stone Giant around her left eye, and by focusing some of her mana into the Rune Chista can tap into its power. This allows someone with little to no magical training to have access to incredibly powerful abilities far beyond what they could achieve on their own. However it tapping into the Rune will drain its innate 'power' which must recharge after a set time.
The most 'basic' (though I use that word lightly) is a charm spell. The Stone's Gaze. This spell can hypnotically charm a creature that looks into her eye, lulling them into a dreamy stupor for about a minuet. That may not sound impressive, but a full minuet is a lot of time to be in a mental fog next to Chista and her appetite.
She can use this ability several times though as explained earlier, it will require more and more Mana each time putting a strain on Chista) Chista: Relax...you wont be worried..pattin her belly its ok am with you...