Maxing Mihawk question

During the last MH-raid i went (a little) crazy and farmed 66 Mihawks in order to max his special.
Originaly i planed waiting for next double-special-lvl-up event to be sure. But with Blackbeard just around the corner and no such event in sight i think about giving it a try.
Sadly my current level of his special is only 3. IIRC i need lvl. 16 for max, so i have to get 13 lvl ups. Do you think the 66 trys are enought for that?

i dont think thats enough unfortunately i didnt had enough time to farm him that much like 
you and also i didnt wait for double special so i lost 15 poster whitout a level up.
so i would say its better to wait till next double special up event for sure maxing up his special its just a waste without.
i also had bad luck with halloween zoro 30 Posters for one lvl up

When I maxed my Mihawk I needed about 75, so 1 level each 5 Mihawks
BUT there was the double-special-lvl-up event, so without the event you will need at least 120 (I would say... but also depents on luck)
so if I where you, I wouldnt use them... Blackbeard you can also get with (for example) 2 gems, farming again Mihawks for hes special will need more gems