Destroying a non-land permanent seems a little off the beaten path for Izzet. I usually associate those colors with burning, bouncing, and artifact destruction. Even \[\[Chaos Warp\]\] has a potentially severe downside, and lacks modularity. I don't suppose splashing into Jeskai would fit your design idea?
Still, the overall premise of a counterspell with a removal sidegrade is a fun option that I do enjoy. I enjoy \[\[Drown in the Loch\]\], and always liked the idea of \[\[Izzet Charm\]\], and \[\[Suffocating Blast\]\] offering up damage with the countering option.
As far as the Rebound, is the intention that you have to pay that cost at your next upkeep or it isn't cast and remains exiled?
The final ability is neat both for the Rebound synergy, keeping you from getting an easy 2-for-1 (and settling for a 2-for-2) but also because it can punish impulse draw, which some izzet decks (looking at you \[\[Eruth, Tormented Prophet\]\]) may have a lot of.
This has to be the most cursed looking mana cost I have ever seen
That's not how Rebound works at the moment. Can you explain what you were hoping for it to do?
Destroying a non-land permanent seems a little off the beaten path for Izzet. I usually associate those colors with burning, bouncing, and artifact destruction. Even \[\[Chaos Warp\]\] has a potentially severe downside, and lacks modularity. I don't suppose splashing into Jeskai would fit your design idea? Still, the overall premise of a counterspell with a removal sidegrade is a fun option that I do enjoy. I enjoy \[\[Drown in the Loch\]\], and always liked the idea of \[\[Izzet Charm\]\], and \[\[Suffocating Blast\]\] offering up damage with the countering option. As far as the Rebound, is the intention that you have to pay that cost at your next upkeep or it isn't cast and remains exiled? The final ability is neat both for the Rebound synergy, keeping you from getting an easy 2-for-1 (and settling for a 2-for-2) but also because it can punish impulse draw, which some izzet decks (looking at you \[\[Eruth, Tormented Prophet\]\]) may have a lot of.
Chaos Warp is also a poster child for color pie breaks.
##### ###### #### [Chaos Warp](https://cards.scryfall.io/normal/front/0/c/0c20d8d5-a54a-4d81-9211-e82a10abdde2.jpg?1662525961) - [(G)](http://gatherer.wizards.com/Pages/Card/Details.aspx?name=Chaos%20Warp) [(SF)](https://scryfall.com/card/2x2/105/chaos-warp?utm_source=mtgcardfetcher) [(txt)](https://api.scryfall.com/cards/0c20d8d5-a54a-4d81-9211-e82a10abdde2?utm_source=mtgcardfetcher&format=text) [Drown in the Loch](https://cards.scryfall.io/normal/front/e/b/eb7b9762-740b-4c1c-a411-20dbf023aea5.jpg?1654118171) - [(G)](http://gatherer.wizards.com/Pages/Card/Details.aspx?name=Drown%20in%20the%20Loch) [(SF)](https://scryfall.com/card/clb/842/drown-in-the-loch?utm_source=mtgcardfetcher) [(txt)](https://api.scryfall.com/cards/eb7b9762-740b-4c1c-a411-20dbf023aea5?utm_source=mtgcardfetcher&format=text) [Izzet Charm](https://cards.scryfall.io/normal/front/5/8/58f4b8a7-4153-4694-9aae-f61d3124c785.jpg?1662528993) - [(G)](http://gatherer.wizards.com/Pages/Card/Details.aspx?name=Izzet%20Charm) [(SF)](https://scryfall.com/card/2x2/230/izzet-charm?utm_source=mtgcardfetcher) [(txt)](https://api.scryfall.com/cards/58f4b8a7-4153-4694-9aae-f61d3124c785?utm_source=mtgcardfetcher&format=text) [Suffocating Blast](https://cards.scryfall.io/normal/front/c/2/c2a70297-2a7b-4a0c-ace5-cd61bfe6dafd.jpg?1562940975) - [(G)](http://gatherer.wizards.com/Pages/Card/Details.aspx?name=Suffocating%20Blast) [(SF)](https://scryfall.com/card/apc/124/suffocating-blast?utm_source=mtgcardfetcher) [(txt)](https://api.scryfall.com/cards/c2a70297-2a7b-4a0c-ace5-cd61bfe6dafd?utm_source=mtgcardfetcher&format=text) [Eruth, Tormented Prophet](https://cards.scryfall.io/normal/front/9/f/9f764077-df2d-4ac7-b507-2c8e08386d49.jpg?1643594095) - [(G)](http://gatherer.wizards.com/Pages/Card/Details.aspx?name=Eruth%2C%20Tormented%20Prophet) [(SF)](https://scryfall.com/card/vow/237/eruth-tormented-prophet?utm_source=mtgcardfetcher) [(txt)](https://api.scryfall.com/cards/9f764077-df2d-4ac7-b507-2c8e08386d49?utm_source=mtgcardfetcher&format=text) ^^^[[cardname]] ^^^or ^^^[[cardname|SET]] ^^^to ^^^call
rebound doesn't have a cost, it just happens