Vocabulary consisting only from characters you are able to read
退化
taika
degeneration, retrogressionsuru
~階
~kai
(first, second, etc.) floor, story, gradejlpt5
係る
kakawaru
(1)to be the work of, to be the result of, to be done by, (2)to concern, to affect, to involve, to relate to; (3)to be affected, to be influenced, (4)to be concerned with, to have to do with, (5) godan, verb, vintrans