Hero Syngergies

Hey all. I'm a filthy casual who's looking to get more into the game. I recently got an IRL friend to play and was wondering if you veterans could help me out with which heroes work well together.

Characters he likes - Valla, Tassadar, Azmodan Characters I like: Lunara, Zeratul, Greymane, Kharazim, Stukov, Malfurion, Abathur

If you would be willing to give me some ideas for combos we can jump into QM with and wreck face that'd be great. Also a little bit about why the characters work well together would really help me.

I am open to learning other chars to so if you see a synergy between someone on his list and someone not on mine lemme know.

Thanks for any help.