As with any complicated issue, these questions alone cant tell you whether or not to mulligan, but they should always be considered as part of the big picture
It can be played either in a green-based ramp deck, or a reanimator deck that brings it back to the graveyard for a lot less than the seven mana it takes to cast
Its a pretty expensive ability on a flimsy body, but its still in keeping with what the card does overall
(20 - 4 = 16) In Commander (EDH), players start with 40 life instead of 20 life
(2022-02-18) An Aura controlled by an opponent does not cause a creature you control to be modified
This time around, the theme is bringing back old showcase frames from previous sets, like the neon frame from Kamigawa: Neon Dynasty, or the storybook frame from Throne of Eldraine