I think this will be decent in the upcoming Odd Mages. RN if you want board clear in Odd Mage, you're limited to Flamestrike and Dragons Fury. And with Dragons Fury in ur deck, it discourages playing low cost spells. This adds odd costed board clear for the decks that don't want to build into the whole "big spells" thing. It also adds support to hand mages without making you draw more cards.
And let's be honest, how many mage spells are actually bad to have added to your hand? 90% of them are just not good enough to be built into the deck. I see this as a Cabalists Tome that affects the board, and usually gives less cards.
Judging at the reactions i already saw below, Alot didn't see the cards working correctly. It actually gives you a card per "overkill" so up to 7 with a full board. This can get bonkers at times! For once i like the rng synergy. You can read back at the revealsite
I initially thought that this card was somewhere between playable and bad, but then realized that the overkill triggers on each minion. That completely changes the power level of the card and lets you do ridiculous things, particularly in combination with cards like Leyline Manipulator and Bloodmage Thalnos or Celestial Emissary. With either of the spellpower minions, you not only clear the board, but you replenish your hand. Similarly, playing the leyline manipulator after this combo lets you do otherwise impossible things via generating enormous discounts.