Theese are NOT viking runes. They are an older Rune alphabet, from around year 500 and earlier. They are called the elder futhark. The viking Rune alphabets have usually only 16 runes and there are several different alphabets from that time.
Avery splits her finger open with a knife ad offers it to Deryk, when he's been refusing to drink from her in fear of the bruises that won't heal. Tempted, he's unable to help himself and leaves more bruises on her again.