Her attack pattern consists of diagonals of single colored blocks making it hard to form power gems. However, like Akuma, she receives a handicap when a human player plays as her. The only way to make up for the handicap is to make large power gems and chain them.

When playing against Devilot hope for a crash gem to get rid of blocks. Since she is handicapped, you shouldn't have trouble dealing with the random block placement unless she does a huge attack.