One last hurray for Izzet Tempo before we lose our favorite flashy pirate:

Pace

The name of the game when playing Tempo is, of course, to control the pace of the game. We decelerate our opponent with Whirlwind Denial, Lofty Denial, and Miscast as well as Petty Theft, Stomp, and Scorching Dragonfire. We accelerate ourselves with fast threats like Brazen Borrower and threats that grow like Brineborn Cutthroat and Phoenix of Ash.

This deck is probably the slowest variant of Izzet Tempo I've played since before Theros. This is largely in response to the current shape of the meta where we can't close games fast enough against current ramp decks like Adventures so we need cards to help us to continue to draw and play the game longer.

Tricks

Gadwick is often how we find lethal and how we survive until we find it, converting all of our blue spells into spells that tap a creature. In the current meta this can be very relevant as quite often there are a small number of large threats we are facing, for example with Uro, Titan of Nature's Wrath or Beanstalk Giant in the Adventures decks, or big stompy things in Mono Green Stompy like Questing Beast and Yorvo, Lord of Garenbrig. Most of our spells are blue and can be played at instant speed to help enable Gadwick to do his thing. The few main phase spells we do play happen to be red anyway: Bonecrusher Giant and Phoenix of Ash.

Phoenix of Ash is a good top deck after turn 5 or so and often is very helpful in closing games quickly or as a recursive blocker if our opponent is the one on the beatdown.

Lethal is often found with things like Gadwick tapping blockers, Phoenix of Ash pumping, bouncing a potential blocker with Petty Theft, flashing in a Borrower on our opponent's end step, or of course Embercleave. You may even want to run 2 cleaves in this deck.

No Hard Counterspells

There are no hard counterspells in this list. Having a turn 2 counterspell to hit important spells like Lucky Clover when we are on the play or Yorvo, Lord of Garenbrig when we are on the draw is important, but we also need a more general counterspell than Negate and a counterspell which can still be relevant in a longer game, unlike Quench. I've settled on 4x Lofty Denial in the 2 mana slot because it splits that difference in a very relevant way, and we have enough fliers to enable it (who can be flashed in to turn it on if necessary).

Whirlwind Denial is another very important counterspell for the deck, and is where you might ordinarily expect a hard counterspell to live. The dominance of Adventures right now makes this a very good thing to have. We cannot reliably hit a Lucky Clover before it can resolve, unless we are on the play and happen to have a Lofty Denial to hold up on turn 2. So we must deal with it after it's resolved and Whirlwind denial really shuts Clover down. It also deals with the card draw and life gain on Hydroid Krasis is seeing a lot of play in these final days before rotation in a lot of the ramp decks, not to mention many relevant triggered or activated abilities on cards like Priest of the Forgotten Gods or planeswalkers.

When we get into the late game, we are stuck with counterspells that may not work. However, there are many interesting and relevant plays you can make in forcing your opponent to tap out in order to resolve an effect, so the counterspells aren't dead. They also prevent your opponent from playing an Ugin, the Spirit Dragon as soon as they've ramped to 8.

With all of this in mind, you want to be closing games before your opponent can be sitting on enough mana to be able to cast a spell like Nissa, Who Shakes the World or Ugin while still holding up 4 mana to pay for the counter.

Miscast can be a relevant spell when denying single target removal against an important threat like Gadwick or a Brineborn Cutthroat, and the ability to hold up only 1 mana to protect something can be very nice for this deck as we often have ways to spend all- or most of our mana on each turn. Hitting an Extinction Event or Shatter the Sky can close out a game. However, it is very often a dead card in hand. You could easily replace this with a hard counter or even a mystical dispute. If it's dead in a specific match you can use it to counterspell your own spells in order to get an additional trigger on Brineborn Cutthroat or Gadwick. We really wish this was a Spell Pierce tbh.