What is the Technic you use to manipulate the ennemies ?

Do you mean to control the ennemy unit ? (Ennemy control Glitch) https://fireemblem.fandom.com/wiki/Enemy_control_glitch#:~:text=Advertisement-,Fire%20Emblem%3A%20The%20Blazing%20Blade%20Glitch,control%20the%20enemy%2FNPC%20units.

Or to manipulate the RNG/Luck (ennemy miss, level up, critcal hit,...) ? https://forums.serenesforest.net/index.php?/topic/28299-how-to-manipulate-the-rng/

Both are used in the speedrun and very usefull. It's not easy to understand how the rng works at first but then it will be cool to use it eh eh. I will send you a PM.