BioShock Infinite: The Complete Edition

There are a total of 15 waves in each Arena. Raven's Dome is the third Arena that you purchase and is intended to be the fairly difficult. As with all the others you do not need to complete it flawlessly but quitting requires you to start over. Blue Ribbons are not required. Between each wave you are given either a piece of Gear or an Infusion. At this point you should be decently upgraded so it should not be too difficult.

Dying during a wave and continuing from the wave restarts your score but does not affect the achievement. This can definitely be ground out one enemy at a time. Dying causes all remaining enemies to go back to full health but anything dead stays dead.

Undertow is your best friend for quick kills as pushing any enemy off the arena one shot kills them. Bucking Bronco/Undertow Combo makes it easy to throw enemies long distances as well.