Multiplicative scaling is very strong. Enjoying killing enemies? Would you like to kill them even more? Cruelty may be the card for you. Solid upgrade as well. Cruelty tends to make it into decks built around Vulnerable synergies which haven't quite found enough Damage or Block to survive Boss fights yet, in which case it does a good job of speeding you up, but it's quite awkward to draw in faster fights, and unnecessary in your best decks.
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