Light : This one is going to need lots of light.
Water: This fella is used to drought conditions so be really mindful to not overwater him. Let the soil dry out before you reach for the watering can. Bottom water your Mont Blanc by filling a saucer or similar with water and sitting him in it – pot and all.
Humidity: You don’t need to worry about any extra humidity.
Temperature: Should be fine in cooler temps. Like with any plant keep him out of the way of a draft.
Food: You can feed him once in the spring/summer with cactus/succulent fertiliser.
Toxicity: Pet safe.