It mostly suffers from a mono-colored identity and the fact that Captain Sisay is an almost strictly better version of this effect
The fact that Nissa is drawn to be bending backwards unnaturally shows how dire things are for the rest of the Magic multiverse
If you sacrifice Treasures to cast Captain Lannery Storm, its last ability won't trigger for those Treasures
Yes, you lose some life every turn, but The One Ring is also indestructible, making it extremely difficult for your opponents to interact with, and you really should have some bounce spells to maximise the potential of The One Ring (and to not lose too much life)
The big difference here is that Sneak can apply to non-creature spells, too
On attack, Teval mills three cards from your library and puts a land card from your graveyard onto the battlefield, and whenever a card leaves your graveyard for any reason, Teval makes a 2/2 Zombie Druid