For me, Varina falls into the third commander problem where she no longer helps the theme at all but is instead tossed in as a bonus
Its the easiest because i have a definitive opinion about it, and the hardest because I honestly was so disappointed with the product I got, despite this particular one being the Rise of the Floodborn box I was most excited about
If that creature leaves the battlefield and comes back, it resets the exhaust ability so it can be used again
Its got a big butt of its own, and definitely deserves a place on the list
It allows the player to draw two cards at the cost of discarding either an artifact or two cards
During your opponents turn, you get to perform any actions that you could normally do during your turn, but during your opponents instead