NERD POST ALERT!
Sit back, relax, grab a snack, this is going to be a long one. And if you aren’t a Byzantine fanboy, maybe this post isn’t for you. 
Disclaimer: Developers have done a fantastic job with the Byzantines from the time of Age of Kings and I want to make a claim that this is not a complain rant, just some suggestions about changes that could be made. Also, and it might sound far fetched, but I personally believe that one of the reasons Byzantines are now more acknowledged nowadays, is because of age of empires.
Having that said, I am perfectly fine with Byzantine the way they are. They are a balanced civ, suitable for low as well as high elo players. Also they are one of the least changed civs in game throughout the years, so it feels a little bit left out.
My suggestions are about both cosmetics and balance. So let’s start with the balance.
1- Fixing the the more HP on buildings bonus(40% post imperial age). Primary this bonus benefits castles(and town centers to an extent), but at the same time Byz lacks masonry and architecture, meaning that their castles, in practice, are almost the same with a fully upgraded generic one. It’s like they get masonry and architecture for free and nothing more, which alright but not that special.
I think that this needs a small buff. Not more HP, maybe some extra melee, pierce armor to offset the lack of the 2 missing techs.
2- The Greek fire. Imo this is one ‘‘must’’ fix. I’ve made of video demonstrating the extra range of the fire ship, does less damage since the extra range changes the arch of the projectile to the point it misses the target, unless of course the enemy is clumped, so the ‘‘missed shot’’ will hit the next-to unit.
It is helpful on dromons though, but not at Bombard Towers. The extra blast radius of the towers is almost useless, since you rarely attack bombard tower with melee units, if you do, you will most likely use something like paladins that can take the strong damage. Again in such a scenario the Greek fire, does not affect the defensive capability of the bombard tower.
So to me, either the extra range of Greek fire, should be fixed to be more accurate, or add extra damage? And make the bombard canon radius bigger.
(Despite all this, Greek fire’s special effect looks awesome though)
3- Cataphracts. I remember in Age of Kings, before bloodlines, Cataphract was the second strongest melee cavalry after Paladins. And it was perfectly fine since they were super expensive. Throughout the years, with the addition of newer civs, came new heavy cavalry units and the introduction of blood lines. The Cataphract become from one of the strongest cav units to one of the weakest (against other cavalry). And of course it is an anti-infantry oriented unit, but its expense to fully upgrade doesn’t not justify their role. In fact in late games, if you face infantry it is viable to use Hand cannoneers/arbalesters instead of expensive cataphracts.
So my suggestion is, either they get +1 pierce armor(to withstand a little bit better against archers/raids) or give them 10 more hp, or make the unit itself/upgrades cheaper. Imo these aren’t OP changes and it will not break any balance of the game.
Also, the Castle age Cataphract is totally crap even against infantry. Some extra HP would help.
Now let’s move to the cosmetic changes.
Let’s start with the Champion. It would be nice to give a little bit more flavor to the Byzantines, by resking the champion upgrade, to either Legionaries or even better to Varangians. I am not talking about extra bonus or anything, just a reskin to make them feel more unique(it was a 1000 years lasting empire after all)
Now about the Cataphracts, I would insist that they do need a reskin. Don’t get me wrong the new reskin is great but in my opinion it could look even better. Now it looks like this(first pic on the left)
I think and this is my own personal taste, they should look like more like this. Some random ideas, nothing specific.
They could still use their swords, although spears or maces are accurate too.
Last, and I believe everyone will agree on that, we need more byzantine HERO units. We have Belisarius with a mongol/asian icon and very low stats. I think it’s time for emperors to be added.
Examples could be Basil the II, the bad@ss Heraclius with his peacock feather helmet(he also known for besting Persian Generals in one to one combat) and maybe Justinian or Paliaologos. Many options here with very cool looking figures.
