User blog comment:Deshiba/Twitch - Tweaked/@comment-5883057-20140327221138/@comment-4022742-20140328122210

I didn't say you'd have BOTH, I said you'd have either, announced by the word "respective" ;)

As for the stacks applying on AP twitch; You'd lead with W and end with E while using R and AA in between, in a late game dream you would: Don't forget that your Cask applies 3 stacks late game and you only have to hit 2 aa's for max damage on Expunge.
 * 1) Come out of stealth with ambush and spray and pray
 * 2) Use 1 auto attack with your Venom Cask in the air
 * 3) Use 1 auto attack followed by Expunge.

As for your damage calculation on the twitch damage, don't forget that all of that is AOE in a 900 to 1200 range, so if you get the drop on them, there is no flashing out. I agree, AD twitch deals more damage over time. The burst is just higher on AP twitch, which is a fun game element (imo)