I have a question about Choralis Rune Moth

Hey everyone! :)

I recently received Choralis Rune Moth from a pack and I wonder if it is worth it to run in a magic deck.

I am a bit confused what is meant by "random rune". Seeing as they cost 0 and this creature can generate multiple if left alive, I could be a lot of value, but only if the runes are any good.

Hope someone can give me a bit more information about the runes and if this legendary is a good option to run! Meanpatrick :D