best halloween character?

Best is a tie between Jakob and Sakura and worst is Nowi imo. I'm Saving orbs, I'm waiting for a Binding Blade/Blazing Sword banner.

It really depends i will be very brief

Sakura is the One of the best dagger around After kagero and Olivia. She is the ultimate mage killer (a Better version of Felicia)

Henry is a armored mage with Pretty good offense and res which allows him a good versatility (by far One of the best there)

Jakob is really a Monster due his Attack combined with brave bow and wary fighter, not to mention is really difficoult to kill him due his res,def,hp and wary fighter (the best unit in this banner)

Nowi She is a flier mage which is good for buffs and mobility, her offensive is good but her Speed is average and actually kinda hurt since is bordeline She still has a good position gameplay with every unit not only flier thou

Keep in mind Sakura is really good and If It happens to get her as your First colorless unit instead of Jakob you do not have to be sad since she is really good at Tank and kill mage. The problem is that unlike the other unit she is not special as an armored ranged unit Who bring something new or a flier mage but neverless She is really good but the others are Just too good ( nowi herself not that much but being a flier helps her a lot)

So priority (It depends on what you have or course) is:
Jakob (It depens It you have many Archer unit still First Place) then Henry (same about mage but even so is Pretty amaizing superior to most of mages now), then nowi (especially or you have a good flier team), sakura

Jakob > Nowi > Henry > Sakura

Jakob = Henry > Nowi > Sakura

But they're all good, it's just my preference.

If we're looking at them overall offense, then it would look like this:
Sakura > Jakob ≥ Nowi = Henry

Overall defense, then it would look like this:
Jakob > Sakura = Henry > Nowi

Firstly, I liked the part where Witchling Nowi fills the missing spot as a Red Tome Flier. She's definitely unique of her own right and can function very well in Flier Emblem teams and Raudrblade. Though, I do find her somewhat underwhelming to a degree, but she's not absolutely terrible.

Neko Sakura is definitely one of the best units from this banner by having a dedicated weapon to answer all of the mages in the game. This includes the newly introduced Vampire Henry and Witchling Nowi and Neko Sakura can tank their hits and powerfully retaliate. It's these traits that makes her a deadly unit.

Monster Jakob is arguably the best unit from this banner due to sporting a powerful Player Phase and Enemy Phase builds. His good Attack and excellent overall bulk isn't something you see everyday and he's definitely an eye-catcher. (Yes, he's caught my own two eyes. I can't stop looking at his stats and many possible builds on him.)

And finally, we have our first Armored Mage, a Green Tome Armor, Vampire Henry. Though, I would've liked it if Arvis held this honor to be our first Armored Mage, but this was a very missed opportunity indeed. Although, Vampire Henry's physical bulk is definitely not what I had imagined and is left with good offensive spread and high Resistance. So, there is definitely hope for him and he can run offensively (Gronnblade) and defensively (Gronnraven) like Monster Jakob.

That's how I would summarize each unit from the Halloween banner. I'm sure certain fanbase are likely to criticize what I have in mind for all of these units, but these are just my own honest thoughts and opinions. None of them are bad and they each have their own niche.

As for whether or not to summon from this banner, you should probably save up, wait and see what November has in store. A good tip from Phoenixmaster1 is to wait until near expiry of seasonal banners so you can choose which banners to summon from.