I'm going to have to take notes next time I go in, but some of those mobs are brutal - one in wave 2 hit my Ryu'oh for about 10k. This will definitely need good target prioritisation. My water team is decently strong - 103% assault, 34% defender - and I took so much damage I couldn't get wave 5 to raging before it would've killed me. Ended up getting it to about 30%.

Now, I was a bit stupid and didn't wait for a friend Rudra to appear, that might've gotten me over the line.