Which is the least deadly?

As per question for deadly,
U is more deadly than Z
1. U > Z.
V is less deadly than Z.
2. V < Z.
W is less deadly than U.
3. W < U.
X is more deadly than Y.
4. X > Y.
Y is more deadly than U.
5. Y > U.
Z is less deadly than W.
6. Z < W.
Now from 1 and 2,
7. U > Z > V
from 7 and 5,
8. Y > U > Z > V
from 4 and 8,
9. X > Y > U > Z > V
from 3, 6 and 9,
X > Y > U > W > Z > V
Effectiveness (deadly) X, Y, U, W, Z, V
Compound V is the least deadly.