Who should be best for it druid,Trixie,pixie or someone else
Here's an unpopular answer, but I've been loving Slow Down Harpy Queen.
I use Harpy Queen to pull targets I want to Slow Down lock (AD, Boss 5). Using Harpy Queen doesn't generate big numbers, but for my F2P accounts, just getting a lock is a win in itself.
One of my accounts went from not even being able to participate in Boss 5 and AD, to pulling in low 3 minute numbers. Not a bad deal for just 1 talent addition.
I will concede that I probably could have put that Slow Down on a different hero with similar results, but I don't really use HQ all that much (even on my F2P accounts), and she is really low on the WG/BW list for me.