It says that it takes 4 attack from all enemies, deals damage or explodes gems. Both the other two are spot on, but my fully-powered Nobend Brothers actually take away 17 attack, probably 18 when I get Sverglade 5-starred.
Looks like an out-of-date description. On PC/Mobile it correctly shows all three aspects of the spell scaling with Magic:
This is also on the PS4, if it wasn’t readily apparent.