Flanking. Focus on flanking.

If the player runs, his back is turned, and he will take extra damage from the enemy. This could alternatively be *the enemy uses a different attack when the players back is turned*, such as a cinematic nearly/completely instakilling backstab. This alternative punishes the player for running, and helps lead them towards understanding that they are intended to face the enemy head-on, and find an alternative, non-kiting, non-fleeing, method of taking it on.
If the player runs towards (and behind) the enemy, he will be able to *AVOID* being hit, and also deal more damage to the enemy.
If the enemy turns slowly, this gives the player a bigger advantage to flanking, and it is easier to flank.
Placing a high-contrast element on the back of the enemy will make a very clear *this is my weak spot*.
The weak spot will not be apparant to first-encounter players because the back is likely hidden to the player unless the player runs to the other side of them (towards, but behind.)
This fixes your unintentional *autocombat* issue. As the player must be repeatedly actively moving in order to be able to avoid being hit, and hit the enemy in return.
Facing the enemy head-on reduces damage, as opposed to running away from them (and being stabbed in the back.) This encourages players to fight the enemy in a certain way, and punishes running.

Depending on what you would like, the enemy can either take reduced damage, or be completely immune to damage, when attacked head-on. If feedback is provided to the player that the enemy takes damage when attacked head-on, it will likely take longer for them to figure out that they need to attack the enemy from behind. On the contrary, if feedback is provided to the player that makes it clear that the enemy is *immune* to being injured by the player, this encourages the player to find other ways of attacking the enemy, and tells the player that there is a *trick* to it, or a *weak spot* that must be targetted.

d) Therefore, what i ask is to propose a set of "actions" for the player, or a set of "specific enemy weakness" that will allow the player to win.

Just hardcode the exact set of actions (and timing windows for those actions) the player needs to take, and if they deviate from that, kill them instantly. It'll be just like Space Ace or Dragon's Lair.

I wouldn't play it, but it'll do exactly what you're proposing.

That is a fun question. I designed a bunch of enemies in my carrer and rather than giving you a specific answer I will give you the philosophy I generally follow when creating enemies.

The most important thing is that you don't want the player to feel like he is being tricked by the game. Some of your solutions fell directly into that trap. You want the player to look at your enemy like a challenge he will in the future be able to vanquish not an impossible obstacle.

I saw a lot of your solutions relying on stats boost or other gimmick wich do make your enemy stronger but not more challenging gameplay wise for the player. Your enemy his just... stronger. Stats should generally only be use for balancing (Great example of that is in video game with a new game+, enemies are stronger because of their stats but offer the same challenge gameplay-wise).

I had to create similar enemies in one game (mMetroidvaniastyle). When the player come face to face with the enemy the first thing you most explain to him, with gamepay, is what your enmey does. Once you shown that to player he now knows what to expect. Your enemy most challenge your player ability inside what you shown him.

lets say my player as a double jump ability. Well to challenge that ability i would creat an enemy wich only way to defeat him is by double jumping over him. But if the player tries during the wrong time my enemy will push him back. The player need to wait the right window of opportunity to be able to double jump over him ( Wich again most be communicated to him with gameplay, signs and feeback EX: afther one of his attack my enemy as a pause before he attack again. The pasue his then the windo of opportunity).

Let's say the first time the player encounter the enemies he does not have the right ability to defeat him. He will then have to come back once he has it and then be able to defeat it. (It can be an ability, a weapon, a power anything the player can use)

TLDR: Don't boost stat to challenge the player, challenge the play using gameplay

Hope this helps. If you have any other question on enemy of boss design don't hesitate to message me.

Sorry for bad English :)