The idea for this one is that backup triggers when the creature enters the battlefield, so if you have a card like Cragsmasher Yeti , you can create a copy of it to give another creature trample and two additional +1/+1 counters
The monsters you're creating in this card are meant to represent the people who succumb to "despair", transforming into hideous monsters
In addition to the classic cantrips Id strongly recommend including more powerful and expensive card draw like Dig Through Time, Pull from Tomorrow, and Drown in Dreams
These kinds of effects can really add up, especially if you have a few of them out at once
All in all, this is a solid card for Simic colors and a worthy inclusion in the top 10
Then, any time one or more cards would leave your graveyard, you get to make a 1/1 Insect token, giving it +1/+1 counters equal to the greatest mana value from among the cards that were exiled, making it a powerful addition to any graveyard-based deck