As this doesn't find any of the good red cheat in effects you typically only see this in the Reanimate / Shallow grave lists and those both being black mean this is very much a backup card
Elsa is all about questing, with a perfectly decent 3 strength and 4 willpower that boosts up to 6 strength on the offensive thanks to the Challenger ability
You might not want to run cards like [c]Disenchant[/c] in your main deck, since not a lot of decks play enchantments, but Disenchant is just the right kind of card for your sideboard
Elesh Norn relies on you to build around it a bit, loading your deck with efficient enter-the-battlefield effects
It does take some time of course, but thats fine Its an artifact, which some Blue decks care about, and it puts two cards into your graveyard all on its own, something other Blue decks care about