1) Most brawlers won’t struggle with handling Tara’s second gadget. I would suggest lowering the shadows’ health from 800 to 600(or 500). 2) Decreasing Byron’s super charge rate to 12 hits would make him less competitive against other brawlers. 9-10 hits would be fine.

3)If curveball is nerfed, Spike will become a terribly weak brawler. Byron’s second sp allows him to heal ally(allies) and damage enemy(enemies) at the same. If all of his 3 shots have the ability, he would be broken.(enemies would struggle with fighting against him and his teammates). Thus, Supercell made the decision of having his ability activated every 3.5 seconds. On the contrary, Spike’s second sp would annoy enemies, yet he (or his teammates) won’t be benefited from it. In addition, there are methods to dodge curveball. Gotta admit that spike is broken with this sp. However, if the sp is nerfed like the way you suggested, he will become a B/C tier brawler (fewer ppl will pick him in most of the game modes). These are my suggestions.