Legality depends on the tournament format -- Double Major can be legal in some formats and banned or restricted in others
Good examples are too numerous to count, even recently, but Calix and Ashiok are excellent examples, offering two potentially useful abilities relevant in different situations
(2024-02-02) If an effect refers to a "suspended card," that means a card that (1) has suspend, (2) is in exile, and (3) has one or more time counters on it
And that's a common situation - Ancient Tomb, Guildless Commons, or Temple of the False God can also tap for 2 mana
The Microsoft Gardens as I like to call it is a vastly underplayed land that is viable in many decks, and only needs one busted card to be printed to have people buying it out