If that creature's power is 2 or less when it enters the battlefield but becomes greater than 2 after the ability triggers, each opponent will still lose 1 life and you'll still gain 1 life
This has led to some variation in foil cards over the years, most notably in the sets Future Sight, Lorwyn, and Shadowmoor, which featured darker foils than other sets
For instance, you only cast the room once unlocking the second door is a special game action which just happens to share the same mana cost and timing rules as casting it would
It's full of references to the classic Clue boardgame, though there's perhaps an even greater emphasis on the new-to-Magic cards, which are less Clue-inspired and more just Commander cards that gel with the themes and past mechanics of different Ravnica sets
For six converted mana, this 3/6 enters the field with hexproof from artifacts, creatures, and enchantments