It will let all of your sources deal double damage until your next turn, so that's now on your turn, you attack, your damage-based sorceries and loads more
Youll frequently see some copies of this out of black midrange decks that may have some extra mana laying around should they not need to use any other interaction
Id say its worth the include just for the card draw
I am always happy to hear about your opinion on this topic
3 Emet-Selch, Unsundered Esper Terra Gogo, Master of Mimicry Golbez, Crystal Collector Hope Estheim Joshua, Phoenix's Dominant Kefka, Court Mage Kefka, Ruler of Ruin Kuja, Genome Sorcerer Quistis Trepe Shantotto, Tactician Magician Tellah, Great Sage Terra, Magical Adept The Emperor of Palamecia The Lord Master of Hell Trance Kuja, Fate Defied Venat, Heart of Hydaelyn Vivi Ornitier Xande, Dark Mage
What you really want to do is Saw in Half your own value creature , using it as a sort of sacrifice effect that then doubles the value of that creature