Elspeth is a bit off theme being best for attacking with however she does make tokens and is very good so translates well into this archetype
There might be some things in the works to reach out to the more general community as well, I'll let you know how it works out in the coming days :)
Since it costs five, I wouldn't run anything that costs more, so you can reliably drop it with your mana free impulsive draw
In fact, Katara alone may have been enough to make Harabaz Druid spike, even though she doesn't synergize with it specifically, but fans are likely also banking on there being all kinds of other cool allies in this set - which seems like a pretty safe bet
Each deck is designed to perfectly complement the Dungeons & Dragons: Adventures in the Forgotten Realms set thematically
But the most important sea monsters are the ones that help us catch up to faster decks by slowing them down: allstars like Breaching Leviathan, Scourge of Fleets, and Lorthos, the Tidemaker bounce or tap down the opposing field, letting us catch up to and get ahead of the competition