YOU SAID:

if Jill is Mary Sue, Mary Sue is Bethany, Bethany is Eva, and Eva is dean, then Jill is dean

INTO JAPANESE

ジルがメアリー・スーであればメアリー・スーはベタニー、ベタニーはエバ、エバはディーン、ジルはディーン

BACK INTO ENGLISH

If Jill is Mary Sue, Mary Sue is Bettany, Bettany is Eve, Eve is Dean, Jill Dean

INTO JAPANESE

ジルがメアリー・スーであればメアリー・スーはベタニー、ベタニーはイブ、イーブはディーン、ジル・ディーン

BACK INTO ENGLISH

If Jill is Mary Sue, Mary Sue is Bettany, Bettany is Eve, Eve is Dean, Jill Dean