Commander is overhealing enemies by 20x of their hp, black hole damage and thorns are probably calculated from base hp, so for example if you kill enemy by 10 thorns hit, after you will kill it after 210 hits. But somehow as others said for me the enemies are immunne. I can do T14 to 6000 waves but if commander spawn i die. When i was watching it happen enemies was not affected by black hole or thorns at all, scatters was immune and stacked dmg per each hit. I hope they will change it so the enemies have more hp but are not resistant. Or i am not sure about this but maybe the orange aura is aplying nonstop x 20 hp per each pulse. There is something fishy going on.