Both of these cards take up a lot of life, though, and so they come paired with a health amount of lifegain in cards like Papalymo Totolymo, and Y'shtola's own ability.
Void Winnower is a noxious Eldrazi partially shutting down all opponents in an unexpected way by making evenly costed spells impossible to cast
Tataru Taru A big reason Tataru Taru lands this high in the ranking is its cost, because at two mana, this cute Final Fantasy card has a great chance of giving you lots of passive extra treasures and it's already replaced itself
His +1 is one of the best "draw a card" abilities that any 'walker has
Instead of having individual artifacts with a finite number of charges, they shared their charges
The token being a creature is usually a downside you're going to be fine with accepting, and then occasionally an upside that lets you do something gross