Hey Everybody!
This is my first guide so I hope you like it and let me know if you have any other tips or experiences you would like to share.

This guide is meant to help you maximise your power/energy efficiency while farming for Treasure Cellar Invitations in Strongbox rooms. I will also cover the optimal Treasure Cellar pathing for max gold keys.

Let’s go over what Treasure Cellar is:
Treasure Cellar(TC) is a special area in the Rift UI. It is located under Geocentric on the upper right hand side. This unlocks at rank E after you clear Rift 60.
You can access the TC for ten(10) invitations. These invitations can be obtained from strongbox room chests. The drop rate is very high and I get them almost every time.
In the TC you move from room to room and defeat random enemies. After you clear a room you are awarded a key and you can use these keys to open chests in the treasure room after defeating the boss that spawns after the 3-Minute timer ends. Remember...the timer does not start until you leave the starting room.

Here is a map of the TC.
You start in the green square and the color of the room on the map gives its respective key color.

The keys you get are based on the value of the room you defeat. There are 14 Bronze and Silver keys and 12 Gold keys and you are also awarded 1 of each key for defeating the boss. There are only 12 chests of each key type so when you beat the boss you only need to get 11 of one type of key. Gold is the most valuable of the keys, producing the best loot from chests.

The chests can contain:
Now that you know what the TC is, let's get into how to farm for invitations and the best route to take in order to get the most gold keys.

Invitations drop from strongbox room chests. These are special rooms that spawn in random places when you enter a rift. It costs 10 energy to open the chest and after you defeat the room all items will drop.
They look like these:
When you enter a rift in the starting room there are four adjacent rooms which you can see.
After you enter, view the minimap in the upper right corner.
If you see a room with an orange chest, proceed to that room to find your strongbox. If you don't get a strongbox room, don't worry, you can reload the raid without any energy spent. I’ll cover how to do that a little further down the guide.
Once you enter the room, interact with the chest in the middle of the room. This will spawn waves of monsters for you to defeat.
Once all the waves are defeated the chest will open and drop all your loot. You will hopefully see an invitation on the ground like I did.
If there are any other chests that you can see on the minimap, repeat the process.
Once your run is completed, go to settings in the upper right corner of the screen.
Tap the Challenge button and this will reset the raid.
Once the raid reloads, repeat the process.
Don’t worry if you don’t get a chest the first time. Just go back to settings and hit challenge again until you load a raid where you can see a chest on the minimap.

Now here is where the magic happens...or where the math happens.
This is also where I show you how this is efficient on energy

Each chest will cost you 10 energy.
I don’t know the official drop rates on invitations but it’s very high. Based on my runs I would say it’s about 75% or more.

You get 280 energy a day x7 or 1960 a week. You can use an additional 15 batteries which is your weekly cap. 15 batteries x 40 = 600 energy for a total of 2560 energy. With strongboxes costing 10 energy, this will yield you 256 strongboxes 2560 / 10 = 256
With an estimated 75% drop rate on the invitations, you should get 192 total invitations. 256 x 0.75 = 192
It costs 10 invitations to enter the TC, so you would get 19 runs a week.

If you follow the TC mapping which I will cover below you should be able to get 10+ gold keys from every run. From the runs that I have done, TC chests give an average of 5 batteries per run. This means that weekly you should be able to get around 190+ gold keys and 95+/- batteries. This results in a gain of 3,800 energy. 95 batteries x 40 energy = 3,800

I have not calculated the other rewards you get from both strongboxes and the TC chests but the amount of gear and items you get is substantial.

The Mapping
Below you will see a map of TC. This shows one of many routes that you can take but this route is designed to get you 11 total gold keys and the 12 comes from the boss.
You start in the green and follow the red line. There is a bit of backtracking as you can see however I save haste for those moments. This will allow you to quickly rush through the empty room so you can get to the next gold key.
One tip I use is as you kill the last monster, if your skills allow, run to the teleporter to the next room. With Water Priests you can use tidal soul and stand on the teleporter as the last monster dies instantly transporting you to the next room.

Once the 3 minute timer is up, you will be teleported to a boss stage where you will fight the boss of the level. The boss elements do rotate and you will get either Fire, Water or Wood.
There is no timer for the boss so all you have to do is beat it.

Once you beat the boss, it will open a portal at the top of the room where you can get to the treasure room.

In the treasure room you will find a total of 36 chests. 12 Bronze, 12 Silver and 12 Gold and you will be able to open a number of chests equal to the number of keys you have.
Once you’ve opened your chests you can collect your loot!!

You can see from the picture below that there is a lot of loot to gather and with 19 runs a week you can really help yourself along in the game.
Well, that’s all I have for you.
I hope this guide was helpful and will allow you to progress even faster in the game.

I also want to thank the My Heroes Wiki for some of the information I had gathered and a special thank you to HaoGG and to my guild, Daevites, for encouraging me to do this guide.

All the best