A bunch of scattered ideas for handling candles, given that the hero almost always wants to have only one lit at a time:

• Track all candles separately unless they have the exact same number of turns remaining.
• Merge all candles automatically, but still keep track of each one’s lifetime. (This would enable lighting multiple candles and then having one of the stack burn out.) When you light part but not all of a stack, the game internally picks the shortest candles.
• When candles merge, their lifetimes are averaged together.
• You can’t light more than one candle at once at all. (Not a great idea since it would destroy the mechanic of lighting a large amount of candles for more light).
• When candles merge, the candle with the shortest life automatically sacrifices as much of its lifetime as needed to “top up” the rest of the stack. That is, if the lifetime is 400, a candle with 50 turns remaining will merge with a candle with 375 turns remaining, making a stack of 2 candles with 25 turns remaining; when those 25 turns are up, it becomes a stack of 1 candle with 400 turns remaining.