Make sure to have enough mana up in the same turn to cast Victory from the graveyard so that your Voltron commander not only has double its original power, but also gains double strike, essentially quadrupling its original power
This means that in most cases, Demon-tribal decks tend to have a rather high mana curve
Bracket 2 being marketed as what the power baseline is for casual Commander makes a lot more sense and doesn't really pigeonhole them into making preconstructed decks fit exactly within that one bracket, as well as making sure players can play that bracket without feeling like their deck has to be equivalent in power to a preconstructed deck
There are of course tons of great Izzet cards, Simic cards, and Gruul cards you could include in a Temur deck, along with mono-color staples
Tetsuko Umezawa, Fugitive Tetsuko Umezawa, Fugitive is a two-cost (one generic and one blue) legendary creature