There are 114 cards in the game that include the morph ability, and they all happily improve when the morph cost is paid except this one
Six mana is far too much to spend on a 4/5 flier with no protection and no enters-the-battlefield effect, and its win-the-game ability is almost never going to matter
Not to mention a built-in sacrifice effect can be very useful
When Magic: The Gathering found itself on Kamigawa, a plane that takes heavy cues from Japanese culture and folklore, including ninjas was obvious
Throne of Eldraine Mechanics Once upon a time, on a world not too unlike our own, there lived Knights, Faeries, Giants, Witches, animated
Thats why I recommend aggressively trading and selling the cards you arent using