In a format where you start with 40 life, Treasonous Ogre can turn 4 mana into 12-13 red mana, which is more than enough to combo off against an unprepared table with Underworld Breach, Kiki-Jiki, Mirror Breaker, or Godo, Bandit Warlord
Turning dead cards into action sounds like the perfect use case, though I've seen this be used in a deck that tries to go off with Phyrexian Dreadnought and Greater Good, with some Replenish action, too, hence the two-dollars-and-change price tag
If the creature you control already has a Role that you control attached to it, that Role will be put into its owner's graveyard as a state-based action after the Monster Role is attached to it but before the reflexive triggered ability resolves
In old Izzet Phoenix setups, this card would have been a slam-dunk inclusion
(2024-07-26) Any as [this permanent] enters or [this permanent] enters with abilities of the new tokens will work
Fast lands tend to be great filler lands to bolster an otherwise fetch land-centric mana base, especially for more aggressive decks