First I have to mention, that i’m from Germany, so sorry for the grammar and the spelling, but I hope you can follow my thoughts about ironite.

As i started with the game i came up with the question, whats the best way to spend ironite.

Now i will try to inverstigate the different options:

At the moment you can use ironite to:
1. Convert it into gold
2. Buy sands of time
3. Revive allies
4. Buy souls

So let’s think about every option:

1. If you convert Ironite to gold the best you will get are 2.100.000 gold for 1000 ironite. The ups are, that you can instantly power up allies and talisman if you got the necessary resources. It takes no time and it can be a huge boost for your team especially in the early and mid game.
The downside is, that gold isn’t the biggest problem in the game. You can have 100million gold, but without the appropriate evo-runes and especially the 3* evo-shards for characters the gold is pretty useless. Another problem is, that it’s hard to get 1000 ironite, if you don’t want to spend a lot of real money. And ironite is very expensive. So if you don’t buy it, you would have to wait a real long time to get the best conversion rate, so this is another problem with this option.

2. Let’s compare the first option with the possibility to buy sands of time with the ironite.
Here it will get a little complicated, because we have to make some assumptions and there is no exacts value, which we can determinate.

Let’s assume we have 80 stands of time and play for maximal value. Maximum value in terms of gold is the final stage of the underworld, where you can earn 6665 gold for 5 sands of time. Additionally, you can earn 3* evo-runes, some 2* evo shards, some sand of time and some ironite of course.
When we take all that into consideration we can play approx. 20 rounds the number of the beast with 80 sands of time. I would guess, that you can even play 23 rounds, but lets stay conservative and say 20 rounds.

In the 20 rounds you will earn 133.300 gold plus approx.. 2,5 3* evo-runes which are essential to evolve your talismans. Additionally you will get approximately 5 ironite and many less valuable shards, runes, and souls which will add up.
So if you invest 1000 ironite in the sand of time refill it every time it will earn you about 35 additional turns, which will lead to 4.665.500 gold (I take the ironite into consideration that drops in the level). Additionally you will earn 85 3* evo runes and other stuff. You will also level up faster, but I will neglect that, to keep the things simple.

This would be a better solution, and you would not have to wait till you get 1000 sands of time. You could buy the sands of time every time when you get 30 of it and you want to play a little longer. And the troopers will be thankful too, because they can be used without problems.
The downside is obvious. Because you will have to spend several days in playing the same level over and over again. This would be very repetitive and boring after a while, but it would be more much valuable than buying gold. Another problem would be, that you will become rich, and have a bunch 4* characters with maxed out talismans. But without the 3* evo-shards you cannot evolve them to 5*.

So maybe we can find a better option:

When we use the sands of time and play solely in the last stage of the dungeon we can play 11 rounds and earn 115.027 gold and approx. 1,5 3* evo-shards, 0.5 rare souls, 3 ironite and other less valuable things. If we refill 35 times with 1000 ironite we will earn 4.025.945 gold, 52 3* evo-chards and 17 rare souls, which have a value of 1147 ironite if you compare it with the prices in the shop and the other stuff, which also adds up. This is huge in my opinion !!!

This option won’t take as much time as the number of the beast, but you will get plenty of value. In my opinion this would be the best way to spend the ironite, if you have a team that can consistently beat level 10 in the dungeons. We could do the math for lower stages at the dungeons, but not right now.

After doing this we will have some 5* characters but we won't have the evo-runes to maximize their talismans.

Thats why i will mix it up a little and grind the dungeons and the underworld stages, that i can beat on auto. This is an suboptimal but comfortable/pragmatic solution, which will be differernt for everyone. There are too many levels to consider, so i will neglect this and concentrate on the "optimal" solution.

3. Revive allies doesn’t get you that far in my opinion, unless you use it in the dungeons to get 25 ironite and use it to earn 3 skulls in to open the secret locations. I won’t use this if not absolutely necessary, I think this is throwing ironite outside of the window.

4. With 1000 Ironite you can buy 14,8 rare souls. When you compare this with the dungeons you will find that this is an very suboptimal way to spend the ironite. Especially when you get your 7th wickerdog queen ;-)

So my conclusion is clear. I will spend my ironite, to purchase sands of time and use it in the dungeons and underworld madness. Occasionally I will revive my allies. But due to a bug, I still cannot use this option anyway.

I’m curious what you think about this theory. I could write even more, but I’m afraid that it will get too boring for you to read. I appreciate every critic, that can sharpen my theory :-)