Which heroes are best for new players?

Hi, 

So I am a new player to this game, and I am having so much fun playing Heroes! I saved up enough to get a new hero, which one should I get?

——-———My Playstyle—————

I am looking to climb the ranked ladder, I’m almost at Diamond with only my starter heroes and a few extra cards 

On Plants I enjoy playing Wall-Knight, setting up a blockade and then buffing and healing up with my plants. I also enjoy Solar Flare, but it’s hard not to burn through your cards with Kabloom.

On Zombies, I play Rustbolt, no reason in particular but he can continually pull cards that synergize well together.

TL;DR Want to win Ranked, likes cards that synergize well and go to mid-game

Thank you for your help and advice, friend me @ Neighbor728838 if you want to duel or just chat 😉