Then a massive 7 mana needs to be spent to level up again and this time you can force your foes to lose life equal to the lost life this turn in your end step, which I've never seen anyone get, but it's a double win con, card draw, and graveyard filling in one card, so it can play nicely in graveyard adjacent brews like reanimation and recursion, with the aforementioned Aristocrats and Sacrifice brews as well as in decks with a lot of flashback
The most important thing you need to keep in mind when building a deck is synergy, yes, but also how viable that synergy is
These are all very playable, particular in cEDH, the faster and more interactive way to play Commander
Naya Enchantments plays them as a snowball thats just a few steps shy of feeling like a Combo deck
With the ability to create dog tokens every time you cast a cat spell, Rin and Seri, Inseparable somewhat disrupts the theme of the deck, however, its not without good cause
The Flamer of Tzeentch is a powerful effect that all Izzet spell decks will want to play