You choose a free 10x10ft. square any creature that fits the 10x10x10 space of the dome and has a CR of 2 will rise and follow your verbal commands for an hour after that it turns to dust, if an undead (that fits the 10x10x10 space of the dome and) step into the zone of undeath will heal for 1d4 for each turn it spends inside it

at higher spell slot level, you can rise the CR of the revivified monster by 1 (ex: this spell cast at level 9 can have a CR of 7)