Hearthpwn

In playing it 10x, I think I got Hadronox on the board once.  Still, when he pops, it is a big boost.  Please note - the deck has no automatic way to kill him, so he's subject to silence.  I don't have Ixlid, so I subbed a second Gloop Sprayer.

I had success with this deck in ranks 13-11, but in ranks 14-15 or 10-9, it is constantly facing really fast decks and losing more than it wins.  Biology project early is your best hope.  I think in the higher ranks of any tier and in the legend ranks, slower decks tend to be more prevalent, and the ability to spam the board with huge minions in the lategame is just incredible.

I also like this deck, a beast variant, although I play my own variant with a bunch of substitutions:

https://www.hearthpwn.com/decks/1226423-luiscrs-quest-druid-2019

I have been playing something similar but stuck at rank 11-12.  I will try your version - I tried the recruit, but didn't use the duplicating thing so I ran out of cards too fast.  Also didn't try Biology project - I will.