Battle of the Nile (Main Quest)
This picks up automatically and immediately after completing Aya: Blade of the Goddess. Your viewpoint switches to Bayek, and you'll join Caesar in a hell-for-leather chariot dash out of the city. He'll drive- you'll use a light bow to provide covering fire.
The basic tactic is just to keep shooting. Halfway through, the riders will be replaced by a war elephant, and a little after that your arrows will be replaced by spears, but your constant-fire strategy remains unchanged.
There is a trick, though. In the initial stage, shoot only those riders that get close enough to start passing you.
When the elephant does appear, he'll get stuck behind the mass of riders, and you can finish the rest of the ride with ease (though the frantic dialogue remains).
When the next cutscene clears, you'll be battling along the Nile. Looks warm.
Ignore distractions and make straight for Pothinus, who's riding another elephant.
The elephant has two main attack- a charge and a stomp. Neither can be parried or blocked, as you might expect, so the standard strat is to dance around it, slicing at it's toes. The easiest way to defeat this beast is by having the Adrenaline 2 ability and a good sickle sword. You can wreak immense damage on the hard-to-miss elephant this way, and its attempts to flee make attacking even easier. For a high level Bayek, even a single adrenaline burst can be enough to take down the beast (Note that other elephants in the game will be much, much harder)
Send the Scorpion to his rest, then make straight for Septimius, ignoring the other battles. You can enter the Jackal's little arena by jumping over the sword and shield decoration on the barricade.
Septimius' whole thing (apart from his massive size- where have they been breeding these gigantic Roman officers?) is his spinning morningstar. It's very annoying, but not as dangerous as it seems. You can duck past it with dodges or overpower moves, and you can also block it, a tactic that pairs well with shields that inflict sleep or other status effects on block.
As with Pothinus, sickle blade battle trances do exorbitant amounts of damage, but watch your vector- it's actually possible to knock Septi clean through the wall of his tent, where you can't follow.
As the battle wears on, his morningstars becoming quicker and wilder. At this point it's worth using the warrior bow and light bows to knock off those last few bits of life.
Still, even victory doesn't go down so well here.
The scene shifts to Alexandria, where Cleopatra seems to have Alexander's staff. One wonders if it still smells of honey.
After the various cut-scenes, recriminations, and foreshadowings are over, this mission ends, seguing straight into The Aftermath.