I think you have to find the castle their housed in. Check the wiki. I dont know all the castles for the knight orders off the top of my head.

https://pop3.fandom.com/wiki/Order_of_Eventide > Game Info > chapter already exists in Singal.

The only problem like I said is not finding Eventide patrol, I already have more than 100 days in my save... I just hope it’s not a bug somehow

Eventide patrols are very rare, they fight the dshar bandit infestation and they don't last long.
Iirc, every tuesday at midnight they have a chance to spawn around singal and they are a purple colour.
Make a save before the spawn time, enable cheats and use the see all to see if they spawn.

I think you can use the snake and heretic books to boost rep, try that as its a lot easier then rng.

As KO orders go they are not very good, they used to be but lots of the new orders and revised older orders eclipse them and you can get their armor easily.

引用自 insolent1：

Eventide patrols are very rare, they fight the dshar bandit infestation and they don't last long.
Iirc, every tuesday at midnight they have a chance to spawn around singal and they are a purple colour.
Make a save before the spawn time, enable cheats and use the see all to see if they spawn.

I think you can use the snake and heretic books to boost rep, try that as its a lot easier then rng.

As KO orders go they are not very good, they used to be but lots of the new orders and revised older orders eclipse them and you can get their armor easily.

In your opinion, which order other than the Order of the Shadow Legion is strong in cavalry? I want to try a different order instead of Shadow Legion

引用自 Neptūnus：

In your opinion, which order other than the Order of the Shadow Legion is strong in cavalry? I want to try a different order instead of Shadow Legion

Knights of the Radiant cross are good especially if you increase their stats by spending money, the knights have good armor, shields, morningstars and 2nd best horse after SL.
No Lord has them as personal retinue aside from the lord that owns Ethos and once you take it you and your vassals will be only ones with the knights so paying for their stats to be boosted will only improve your side.

The Sergeants are decent xbows.

The only requirements for founding chapters is owning Ethos and 20k, this means that you can spam chapters in every castle and town you own and when you give them to vassals they will have radiant cross personal retinues.
With the Knights boosted stats they will perform better in autoresolve battles helping your lords.

There where tests done a long time ago and while shadow legion are the best, the valkyries and KoL where a tied 2nd best with the griffons 3rd/4th.

Downside to valkyrie and KoL is that they are used by a lot of lords so paying to boost their stats will have a small negative effect when you or your lords fight against them.
The requirements for founding chapters are not ideal.

Those tests where done before the Order of the Phoenix where added and they are really good with their equipment and good horses.