Having 0 power does help, as decks rarely run 0-power creatures
Jalira, Master Polymorphist's only weakness is it can't hit legendary creatures, but with the right build, this downside is easily played around
Honorable Mentions The One Ring, Teferi's Protection, Perch Protection, Noble Heritage, The Stasis Coffin, and Absolute Virtue are all cards capable of giving you protection from everything which still stops spells and abilities from targeting you
Aside from its mana production and Cycling cost, Twisted Landscape fills the same role as Tranquil
Ayli, Eternal Pilgrim Youre not restricted to walls or defenders with Ayli, Eternal Pilgrim, but they tend to have the high toughness stats that this kor really likes
And with cards like Silversmote Ghoul and Moldervine Reclamation, you draw cards and grow your board at the same time