First, you need to survive long enough to be able to cast two spells in one turn cycle
Personally, I think the card is a bit of a relic from older versions of the archetype, but it can still be surprisingly effective, especially against decks built around Lightning Bolt
Its Swords to Plowshares on a stick, which means flicker decks can have a field day controlling the board with Displacer Kitten, Thassa, Deep-Dwelling, and anything else that lets them flicker it
On top of all of this, Kronk has +1 Resist, which means he takes one less damage any time he would take a hit
Several other cards allow for extra draw or the return of cards to the hand, keeping an Amber/Amethyst player well-stocked and ready to keep the table full
However, it is clearly from the Golgari guild, so Im including it here