Again.
Calliper has a guide with useful tips but thought I'd add my tips as well. For me, this was another pain in the ass achievement. It took me several tries but finally found an easy combo pair.
You'll want to use
Tina-28 for my method. As she has a charge ability called
Pump it Up which activates a boost of energy for you and your team-mate. Hold down
= to use the charge ability.
I then have Hope as my Allie but you can choose someone else you see fit. You'll want to always dunk with Tina-28 for the full 35 dunks to unlock the achievement.
Pick the map
The Ball Pit as you have that Yellow orb for the Mega power that makes you massive. You'll keep getting points for the Mega whenever you dunk almost everytime.
Now whenever you dunk with Tina-28. Immediately do her charge ability. As this will keep you energised constantly so you can dunk. After doing a dunk and using your charge ability, it's key to let the other team score, so your team mate can quickly pass back to you for another dunk.
If you do this. You'll get in control of ball much faster for dunks and you won't be wasting precious time trying to steal or rebound the ball as overall score doesn't matter. Your aiming to get 35 dunks afterall.
Mega Power Tip-
when you do go into Mega form and dunk. I find it easier to move around in a circle straight after a dunk as this normally allows you to pick up the ball quickly for another dunk. sometimes it's luck because the ball does go flying the other direction at times.
ITEMS-
It's random what comes up to buy but you'll want something to boost your speed and have your team-mate have an item that improves passing ideally.
I hope this guide does help out.