Evil, ill are comparable when they mean whatever is harmful or disastrous to morals or well-being.
Evil is the ordinary term capable of use in all contexts and referable not only to deeds and practices actually indulged in or to conditions actually suffered, but also to motivating desires or actuating causes of such deeds, practices, or conditions and to their harmful effects or consequences.
Evil is also the term in general use for the abstract conception of whatever is the reverse of good, especially of the morally good, or as a designation of whatever is thought of as the reverse of a blessing.
Although ill, like evil, may imply an antithesis to good, it is seldom used to designate the abstraction except in a poetic context and in direct contrast to good.
Also, it is now rare in the sense of moral evil. In present use, as in the past, ill is applied chiefly to whatever is distressing, painful, or injurious and is more often used in reference to what is actually suffered or endured than to what may be inflicted or imposed on one.