I know that a lot of people have been complaining about how impossible it is to finish the heroic mode, especially since gree shortened the redemption period to one week only. The change is shocking and all, but I have been able to finish everything with some effort. I'm pretty sure if I set alarms I would have been able to finish the heroic mode each time for free. But alas, I like uninterrupted sleep and I also have real life duties during the day. That in mind, as long as you are fairly diligent and efficient with your time and resources it is possible for an advanced member (lv100+) with a handful of decent armors to finish the heroic mode with just a handful of gems. I don't know exactly how many I used, but I'm pretty sure the number is fairly low - maybe 100 gems or less. Considering that the stats of the plus version heroic armors rival T25 epic+ armors, I think that's money well spent.

Here are some tips:

1. Try to log in a few times during the day, even if it means you only play for a few minutes. The more you spread out your log in instances, you are using the most out of free energy.

2. Instead of finishing one world at a time, skip around as you drain your free energy on all your 6 knights, with elements of your knights aligned most favorably against the elements of the monsters you are fighting. Don't worry about the elements of the minions - try to remember the elements of the bigger monsters that do special element drops as they have the highest attack power. Make sure that your knights don armors with counter elements.

3. When you have a full bar, work on the harder level first (get that out of the way) and then as you are left with a handful of knights with partially full health bars, work on the easier levels.

4. Only use potions on your main knight, and only use potions when you are trying to top off your xp bar to the next level. Learn to gauge your xp bar and use just enough potions to bump you to the next level.

5. When all of your knights are at zero energy, wait a few minutes until the knights have a handful of health points back. Then line three of them up for a difficult level using appropriate counter elements. Run through the level and when all of your knights die, click yes to 5 gem regen option. All of your 3 knights will be replenished with full health bars (this is equivalent to you purchasing more than a dozen potions using only 5 gems)