Canonically, Patchouli's ribbons are magic amplification talismans, which is why she sticks them to every piece of clothing or strand of hair she can, since they apparently stack effects.
... Just explanation for those who didn't get the significance of why Patchouli left Koa one of her ribbons.
Agni Shine!...I'll do my best!Lady Patchouli...I won't let you get away!