Also Desert Maiden is top tier because female is much more common than male, and combined with the anti Riding and anti Chaotic CEs the vast majority of servants are covered.

But we can't combined CE, no? Also I can't used the CE against figure like Sigurd and Dioscuri.

Yeah, you can't combine, you'd just use whichever one is relevant for that fight. Dioscuri are covered since they're chaotic, but interestingly Sigurd is one of only 19 servants where Fondant au Chocolat is still relevant if you've already purchased it (wouldn't recommend for anyone who hasn't). This isn't even counting the mixed stat power mod CEs, which IMO aren't worth using, but you could if you wanted to. They wouldn't be a huge amount worse than some other options.

So I can't use Desert Maiden? Man, that's useless. Thank God it's just event CE, not gacha CE 👀

For van gogh, starting NP is the most common to use. As support either kscope or just ley line can provide you support np for your main dps once or twice. As dps (solo) you can use starting np or dmg CE with crit/atk/specific dmg. The preimum selection maybe like true crimson spear, club argonauts, etc2. Event CE like pionering oni, bloosom under crimson sky, fist of hail, holy night sign, etc2, and specific dmg CE can be used depends on the gimmick or enemy.

Specific dmg CE always came with specific enemy, its works case by case. So it's not like they are useless or to good to use too. For example desert maiden, if the enemy is female then ofc desert maiden is better bc that 30% female dmg for NP and card(crit). Non specific like holy night dinner only cover 15% NP and 15% crit. Even premium CE still have a lower spec than specific CE. (Edit: forgot that premium CE have something like honey lake with better dmg :p)

So, if by any chance the enemy is female (either solo or multiple boss), then desert maiden is better. For solo its clear, but for multiple we can just hope there are no single male/unknown mixed in the pack lol.

You wouldn't recommend Fondant Au Chocolat? That's interesting, because from LB 4 to LB 7 (and even OC 1), we're facing with many divine enemies.

When it comes to CE.

Free, farm-able CE are rarely worth to Lv. 100. Lv. 15 (by MLB) is fine.

Consider to push it above only when it have focused ATK only stats.

For damage CE talk outside the obvious Black Grail, despite several people claims, CE with special damage like Fondant, Desert Maiden do fell from their overall importance.

From player side:

TA and solo players wanted better numbers (e.g. Versus, Poster Girl) or good secondary effect to justify it cost (e.g. Honey Lake come with Invul. Pierce). Favorite players OTOH wanted CE that play to their favorites strengths since damage is covered by NP 5 (e.g. Mud Rain for Bhima clears, Salvation for Aesc clears, Failed Immortality for Chen Gong clears or the case that rarely people understand, Indra's Bond CE).

From Servant side

There's Monte Cristo who is a walking Honey Lake, Marie Alter rewarding turtle team, Richard and Sigurd rewarding players that committed to Buster min. turns while Saber, Morderd and Arthur served as the middle ground. Sugitani have "Anti 5* Saber" written on her kit. Shakespeare and Darius now W Koyan Oberon viable, etc.

As a result, CEs like Fondant, Desert Maiden felt like a dead weight once it 50% NP used but to Servants that you know you'll have no problem constantly relying on their normal attack card. People like KH, Cu, Enkidu, or account with no access to developed supports, a smaller group compare to 3 or 4 years ago.

Fondant looks awesome at first, but once your account developed further, it's not that tempting anymore unless it came with solid secondary effect like Taigong Journey CE that released during Noah Ark's Raid.

I'm using Fondant Au Chocolat at Taisui Ordeal Call CQ, and it works really well. Sometimes it's better to have multiple level 100 CEs just to get more depth in case there's a fight that limited the CEs.

It isn't that it doesn't work well. If you already have it it works quite well, but isn't worth buying if you don't have it because as more free options become available there's only 19 servants covered by it, but not covered by the free options, and for those servants it's never the best option, it's just a good option. And you could use the curse one or Honey Lake if you have it if you wanted to go the power mod route.

I'm not talking about the servants. I'm talking about the enemies. LB 4 enemies is mostly Divine. Atlantis is also Divine. Olympus, lots of literal God, definitely divine. Iirc, Koyans and Douman also have Divinity, Cernunnos also have, Gods in LB 7 also have Divinity, and lastly, Durga/Kali. There are lots of divine enemies, not just servants.