First up, there's Olivia, Opulent Outlaw, who makes treasure tokens when outlaws deal combat damage, and can turn that treasure into buffs for her whole gang of misfits
Beyond this, her stats aren't remarkable, but they complete the package sufficiently well, and the ability to get her on the table for 5 ink instead of 7 with a Shift ability could make her a great deal
Plus, sometimes you'll use it to win a combat
Every color has access to it as a solid way to either make its creatures modal (via X-spell creatures that enter with X counters) or capable of growing into the late game
When you spend this mana to cast an instant or sorcery spell with mana value 3 or less, you may exile that spell instead of putting it into its owner's graveyard as it resolves
Modern Horizons 3 brings a heaping helping of exciting new cards to Modern, one of Magics most celebrated formats