The two Mythical Companion Beasts were the Lucky Stone Sprite and the Lucky Clover King. Like the Baby Tiger, they had a Luck Life Providence, but they added more Luck than the Baby Tiger.
Stone Sprite +9 Luck, Lucky Clover King +7 Luck. The six Epic Companion Beasts added 3 to 6 Luck.
As for the two Legendary Companion Beasts, they were both +1 Luck.
The Lucky Stone Sprite's Companion Form was a bracelet, the Lucky Clover King was a ring, and the Epic and Legendary Companion Beasts were myriad in nature. Zhou Wen did some calculations. Apart from two Companion Beasts that conflicted with the Companion Beasts he had to use, there was one that didn't have a Companion Beast form. The rest could be used together.
Zhou Wen was somewhat surprised by the Mortal Companion Beast. This was because the Companion Beast didn't have a Luck stat. As for why it was sent over as a Luck Companion Beast, Zhou Wen guessed that it had something to do with its skill.
