
Update: I have restyled this puzzle as a multi-puzzle set, comprised of five puzzles of increasing length. Also, a new hint.
Complete the last line in each of the following five series:
Puzzle 1:
"Using" is E
"Desist" is I
"Visits" is E
"Design" is ???
Puzzle 2:
"Asia" is H
"Cuffs" is S
"...