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)
When summoned, Kaldra immediately equips all three of its signature items, resulting in a 9/9 indestructible, first strike, trample, haste monstrosity that can exile those it defeats in combat
The Book of Exalted Deeds is a less threatening lifegain payoff, but adding a Platinum Angel effect to an indestructible creature like Avacyn, Angel of Hope turns winning the game into a real head-scratcher for your opponents
If you sacrifice Treasures to cast Captain Lannery Storm, its last ability won't trigger for those Treasures
The fact that Nissa is drawn to be bending backwards unnaturally shows how dire things are for the rest of the Magic multiverse