The 4th game in the series, Genealogy of the Holy War, introduced one of the most important mechanics in Fire Emblem: The Weapon Triangle. This game also marked the debut of the Swordmaster class, as well as the first feamle to use only swords: Ayra. This game had a lot of good in it: the plot, the music, the characters and the OG S-Supports. However, this game, along with Thracia, are actually my least favorite in the series. What Genealogy did right, it did it amazing. But there were a lot of problems i had with this game:
Cons
-Minimum promotion level is 20 and i'm really impatient when it comes to level ups (this is a personal thing, i know)
-Level does not reset upon promoting and the level cap is 30
-The level system also renders Corpul useless as he joins when the game is practically over as a lv.1 Priest.
-Healing items such as Elixers don't exist.
-Maps are huge (i know what they were going for but the prolouge does not need to be the size of Bionis' Leg)
-Trading has been replaced with something else: the Pawn Shop. Basically, if you want to trade a weapon or staff, you can't do it directly. You have to go to your home castle, go to the Pawn Shop, sell the weapon, and then have the other character buy it back. Because you know, Trading didn't work so well.
-The Love System, while good, was really vague when it came to telling you how close two characters were.
-A quarter of Ch.7's map is a desert.
-Nearly impossible to save villages since bandits start out either next to them, or on them.
-Great Shield activates too often which makes fighting Generals a pain in the ***.
-Why can enemies switch weapons during Player Phase?
-Mounted units are broken, as they basically had Galeforce before Galeforce existed. And this made fighting a squad of cavaliers, pegasus knights, etc a pain since they would take turns stabbing you to death.
Sorry about this rant but i did say i'd be giving my thoughts on each game. FE4 is still an amazing game, and if you can get past the problems i listed, you'll enjoy it way more than i did.