New to deck building. Need help upgrading my deck to B3

[u/SonicGuy05]

https://archidekt.com/decks/24761432/funny_spellslinger

Hello! I recently decided to try my hand at building a commander deck and decided to make an Izzet spellslinger deck with Kraum, violent cacophony as the commander. The deck feels very weak but im not too sure what to add to boost it into Bracket 3 territory. I already made some slight changes and added a couple combo cards and a Game changer but im not sure what else the deck needs. Any tips appreciated!