This one's good, but I think the CE that use Mana Prism in Da Vinci Shop (like Drunken Jalter and Sumo CE) is better.

I just looked at them. I agree, Golden Sumo and jalter’s ce, Holy Night Dinner, aren’t linked to a specific card type, so they are probably better to level up

Do CE effects stack with skill effects?

Like how an attack and card boost multiply into each other. Would a CE attack boost multiply into a skill art card up?

Also, I was looking at the other cards I could get with cubes, and Golden Carp, the star bomb CE, also looked useful. I only have enough cubes to mlb one CE from the shop. I may buy golden carp and level up Forest Warrior. Buster would still be good on most quick and arts servants since brave chains are so good and buster cries are always useful.

I think it's Multiply, because they are considered two different types of buff.

Is golden carp the best star bomb ce? Or is there another I should look at? I have other star bomb ce but the 50 np charge seems more useful for supports.

Depends on your play style. If you want both, then you can choose Golden Crap. If you just want instant stars, then you can choose other CEs.

Kscope is a great one.

MLB gives you 100% Np battery.

There's honey Lake, curse honey Lake, lot of event CEs with 50% np charge etc.

I just names the top ones that came to my mind(whose names I remember 😅).