Dheth I do not agree with what you say. Natural selection, in fact, exists and I show it to you. Without spending money how many gems can you get there? Only few… and certainly not enough to face the 10 skulls odyssey. Normally I (and i’m a strong player) use 21 gems every island and in total there are 25 islands for about 525 gems. If we then consider that we need to prolong the celestial boost etc … your statement is wrong.
Returning to the topic.
If I face the Odyssey with the celebrated hero who is maybe level 15/16, you can have all the cold blood you want but the chance of dying is high, I would say very high. It’s not about figuring out when the right time to use the invocations is, because it also happens that by dealing with my strongest hero, after using the invos with the energy to the maximum, I died few seconds later. I believe that for the invocations the same parameter of the powers should be used, that is, after the resurrection, they should continue. Just to not throw the money, do you understand what I mean?