It's worth noting, also, that you can semi-rig this one. Additional waves do not spawn until the Troll-type enemy at the very end of each wave is killed, with two Trolls present at all times beyond the first wave. So you can simply kill everything in the first wave except the Troll (which has several times as much HP as everything else), and then freely focus on the remaining respawning wave (including second Troll) from there on out.
Black Mage's AoEs, such as Stonega, easily kill entire clusters in one go.
Also, yes, congratulations on the completion!