If you want that cheap-but-high-stakes extra turn spell, you have better options
The absurd amount of card advantage that Necro offers, essentially allowing you to convert life into cards, makes it one of the strongest card-draw spells that has ever been made
Dragonkin Berserker The strongest boast rare, Dragonkin Berserker threatens to quickly take over the board by acting as an aggressive 2-drop that creates 5/5 dragons with boast
The first is mobilize, the Mardu mechanic, which is a creature mechanic that triggers when a creature with mobilize attacks, creating a number of 1/1 red Warrior creature tokens that enter attacking
Its alternate casting costyou exile a green card rather than pay 4 manamakes it a free answer to cards like Chalice of the Void, Leyline of Sanctity, or Ensnaring Bridge
I would seriously consider running that in a combat-focused white deck, and its cantrip is balanced by the fact it wont always kill something swinging at me