Best Brawlers for Each Game Mode in Nulls Brawl?

I'm really into Nulls Brawl and I'm trying to improve my gameplay. I was wondering if anyone could share their recommendations for the best Brawlers to use in each game mode.

Whether it's Gem Grab, Showdown, Heist, Brawl Ball, or any other mode, I'd love to know which Brawlers perform best and why. Any tips on strategies or specific builds would also be awesome!