Well, a new PBEM! And I did choose Persia from my picks, purely for fun and to test out its powers in multiplayer game!
A closer look of Persia:
Everyone freaks out when reading that all units of Persia gains 2 extra movement points when declaring surprise war and instantly declares Persia a overpowered civilization.
However after analyzing it calmly, some shortcomings shows up. Other player can actually prevent me triggering this power by declaring me war instead me declaring them a surprise war.
Moreover if other player never sign peace with me, I can't trigger its power ever again, so there is room to screw up me. I do have a little solution against this scenario:
Player A declare war at me and prevent triggering Cyrus's power, I declare surprise war at player B and use extra movement to invade player A. Though downside is that I gets in 2 vs 1 situation at wrong end then.
Conclusion: 2+ movement when declaring war do look overpowered at first view, but there are ways to screw up with it, so it is manageable for my opponents.
In my opinion the true overpowered ability of Persia:
no occupation penalty! So when I conquer one of my opponent's city, I can make full use of that city from start and I don't suffer 75% penalty of all yields in occupied cities. In PBEM 2 I did suffer greatly from occupation penalty at end of game, I did conquer 11 cities and all of them didn't really help me besides owning them and I think that I managed to complete handful a building or units in occupied cities which did contribute very little in war against oledavy and Woden. With Persia it is going be very different story!
Satrapies: Extra trade route when reaching Political Philosophy civc and +2
and +1
greatly contributes with growth of my empire. Don't underestimate one higher road level, combined with 2+ movement I can carry out a truly surprise war or move my units over large distances. If I decides to add Great General here, it would be terrifying.
Pairidaeza: unlocks with Early Empire civic, so I can build it fairly early and I can possibly skip building monuments for culture. Instead I can gain culture from trade routes (see Satrapies) and building Pairidaezas. Pairidaeza can't be built next each other and moreover they offer adjacent bonuses to holy site, theater, commercial district and city. So a city planning for long term is needed here to not screw up, although Pairidaeza can be removed since it is a improvement unlike districts which can't be removed. The appeal bonus gained with Pairdaeza allows me to aim for cultural victory with tourism if game drag till in modern age.
Immortal: this is probably most weird unit of civilization 6. It is a melee unit and a replacement for swordsman, but it attack is ranged. Which means that I can't capture cities with immortal (in test game I was wondering long when I can't take a defenseless city with 4 immortals
). Which mean I need to back up immortal with horseman, heavy chariot or warriors to able capture cities.
Also a wacky thing is that despite Immortal using ranged attack, it promotion tree is based upon melee unit, which mean that Immortal won't gain extra ranged attack through promotion and is stuck at 25 ranged atk. Normal archer with promotion get 30 ranged atk.
True strength of Immortal lies in its resilience, with strength of 30 (still weaker than swordsman which fields 36 strength) it can survive strikes which normal archer would die. This way Immortal can pile up promotions which often boosts his melee (defensive) strength. Also his range of 2 allows me hit enemy melee units earlier and damage them before engaging melee. Enemy archers lose against Immortal due having lower strength. Horseman can rush in and win battle against Immortal but not one shot kill it with one or two horses, so Immortal can counter attack here.
Therefore I need to play strategically, if possible find choke point or hills where Immortals can attack from and make difficult for enemies to reach Immortals fast.
. 
per turn, nice. Which mean after I finished Animal Husbandry, I went for Pottery and Irrigation after Animal Husbandry to able improve citrus for amenity with my first builder soon. I shall improve one wheat farm, horse pasture and after that plantation at citrus tile.