Elusive four

[Elleabridges]

I can't figure this one out. Now of course I didn't write it down which ones I killed but I'm almost sure I killed them all... is there anyway to figure this out?

[Plqgue]

Your memory is the only way xD

[Meozulete]

you need defeating 4 mini boss 1 in wt, kt and mk, 2 dead city 4 and 5, 3 kraken isles 3 and 5, and the last boss nord 3, 4 and 5

[ΛVΛDΛΚΣDΛVЯΛH]

If you forget, you have to start over from the beginning. That's the only way. I believe there is medicine out there to improve memory. If i ran into an elusive boss before, I'm pretty sure that the excitement would bolt the memory into my brain. Besides skratch cuz he's like the red-headed stepchild of the 4.