Once it's on the battlefield, all of your stuff becomes free, which almost always leads to the game ending in short order
Youre turning Nami into a 7,000 Power Leader, making it difficult for your opponent to get their attacks through
Starnheim Unleashed is perfect for the currently developing Angels tribal decks while also being a good inclusion in many control decks
The life loss for your opponents will be fairly negligible, and every once in a while they'll get an extra ETB out of it, but none of that will compare with you returning your Myr RetrieverMyr Retrievers or The One RingThe One Ring every turn
If you manage to ultimate her
They are the draft chaff, the bulk, the cards you store in white cardboard boxes and forget about for a decade