Wit's End: Increase flat MR, remove stacking MR, Keep MR shred and increase to 6 stacks.
40% Attack speed
50 Magic Resist
Passive: 40 on-hit magic damage
Unique Passive: Basic attacks (on-hit) grant +5 magic resistance and reduce the target's magic resistance by 5 for 5 seconds. Stacks up to 5 6 times for a total of +25 magic resistance and 25 30 magic resistance reduction.
Better build path:
+ 
+ 
+ 780g = 
Strategic identity achieved.
+ 700 =