Guides & Tips Event [GUIDE] Heroes, Level it? Keep it? or Merge?

I'll preface this by quickly absolving myself of all responsibility by saying; this guide is strictly the observations and opinions of a mere top 25 player, but to those who are just starting out this might save you a few head bashing moments of regret.

Without further ado let's dive in and we'll start with my mistakes. First mistake I made and probably one that others will make as well.
Merging 1 stars without-paying-any-attention-to-them-because-the-game-tells-you-that-they're-common-and-not-worth-keeping. That is most definitely false! While it does recommend you keep coco, especially for the Hero Master Event going on right now, as well as the fact she has the highest int among 1 stars, there are other 1 star heroes with passive skills you will want to keep.

Specifically the ones that you will later level up that increase your resource generation.
Pay attention to these names:
1 stars to keep: (and yes there ARE similar heroes in 2 star and above, like Deva, but we won't cover them for the sake of brevity)

-Coco (for previously stated reasons)
-Luna (passive gold production)
-Mei (passive food production)
-Guillaume (passive gold production)

Second mistake I made, levelling things indiscriminately. This is a bit of a more marginal error. It didn't slow me down that much, but I still wish I had funneled all that exp into coco first instead of dividing it among lots of heroes that I ended up later merging into coco for a bit of exp loss overall. Fortunately you don't lose all THAT much exp when doing this, but it's still wasteful. When first starting out you'll definitely want to have a very focused int hero (two at most) for the first couple days of play. Why? because it will make your upgrading of buildings significantly more efficient, and save you resources in the long run, since your buildings increase at a % rate every build attempt, with a bonus for the int of the hero you used to help build it. This means a strong enough int hero can get you 2 levels or more at once when upgrading a building or defence structure. Or on the flip side once your buildings get higher, you'll only be doing 33% or even more significantly less of a building upgrade per attempt and that hero will bump you up to 50% saving you a third of your resources. One can always branch out later, and probably will, but funnel funnel funnel that exp into 1 main int hero for a while. What about POW and LEAD heroes? Well that's up to you. A bit of variance in play styles is a good thing.

Now then, I've covered my mistakes, I'll round off the guide with a few observations and tips.
Firstly, Merging. There is a neat little building called the knight hall. This unlocks pretty quickly as you level up your palace, and it is where you will train your hero and merge hero cards, at this building you choose 1 hero card to train, and up to 5 material hero cards to add.
There's a neat little function here where, if the material cards and the main card being trained, are of the same stars tier, there will be a 10% per matching stars tier for a "great success", meaning you can get up to 50% chance of great success happening.
This "Great Success" improves the exp gained by 1.25x (and also increases the limit break of the card by 1, something that can be a bit hard to notice for a while.)
You'll want to try to use this to your benefit, especially for limit breaking those higher rarity hero cards.
One final thing to mention. There is a PIL system in the game, where hero cards can have bonus stats that can be transferred to other heroes through the inheritance system. I haven't been able to use it yet myself but from the looks of it, we need to save up 5 PIL heroes to use it. These are rare heroes so make sure to hang onto any you luckily manage to obtain. They look a bit like the image attached below.

Ok that is all, I hope readers who stuck around this long manage to avoid wasting any hero cards with all this information.
Good "kingdom hunting" to you all.

*Edit: Written by Sciolism of Kingdom 2*