Today's starting Heroic Combat Quest l and ll for the newest heroic dragon. However, I am pretty disappointed with the conditions for the second quest because it demands, in the seventh battle, the heroic to be lvl 41, which is pretty frustrated in view of the food update let reaching lvl 40 a lot easier. In addition to this, some others past combat heroic battle quest requested the heroic to be empowered 1 star plus lvl 41, but ONLY IN THE LAST BATTLE. So, I wanted to know whether is possible or not to empower him 2 stars spending about 250 gems in time. If so, when should I spend the gems focusing on spending the minimum necessary?

First, closing this as it is a part of the heroic race, so put all questions and concerns there. Second, as to your question. To spend as little as possible you will need to calculate the time needed to finish the second one without using gems. To get there you will need to spend gems to rush the empowerment of the first one, so it is going to cost you at least 56 gems. You will need at least 24 hours to finish the last 4 stages without gems. So that means comes down to how much cushion time you are going to give yourself to determine how much you will spend to get quest 1 done. Since quest 1 is cheaper then it is best to pay for the speedups on quest 1 than it is for quest 2. If my calculations are correct for me I plan to spend to speed up the last 3 fights of quest 1 which means this one will cost me 180 for speed ups, 56 to empower and 14 for the hatching, which is the 250 you calculated. That calculates down to less than a gem per orbs which is A LOT cheaper then they are to buy them on offer or during orb sales. And no these have never and should never be for free.