Whether or not this card should see play would depend on the specific deck and strategy, but it could be a situational inclusion for decks looking for extra creature recursion options
And this card was legal in Standard
Menace creatures still can only block one creature, unless they are granted the ability to block multiple creatures from somewhere else
Put Lier in a mono-blue deck filled with card drawing, bounce, and removal and you will be the bane of all of your friends as you have at least twice as good of a time playing as they do! The two pieces of art are also incredibly intense, so who is this character
That said, if you have opaque sleeves and a grasp of Japanese, you may just get away with including these unique cards in a deck
Her flip condition is easy to meet in sacrifice-heavy builds, and the planeswalker side sustains pressure over time, a role often compared across the best vampire commanders in MTG for grindy black strategies