How Good is Shark Tooth Necklace?

[D.A.R.K.]

Explain me in a perspective of difficulties:

Normal Pre-Hardmode.
Normal Hardmode.
Expert Pre-Hardmode
Expert Hardmode.

I know what it does, but since I don't know how much armor enemy has, how can I say if 5 is good or not? I could run test before test but that's the point of this Thread, save me that effort.

[InstableMonster]

Check the wiki all ennemies have their defense listed

[Ruinae Retroque Rursus]

useless useless useless and useless

It's awful.

[「 Kaizeron 」]

Mediocre. Just don't use it please, it can be helpful on occasions, but it's honestly a waste of space that could have given you a much more better buff than...

that grey ass ♥♥♥♥ with some spikes on it.

[H11DN-D4NG3R]

On non expert, ehh, mabye for a early boss but its not that impressive on non experts, due to majority of the enemys dont have that much, but an accessory is an accessory.

Getting it extremely early on expert pre-hardmode its good. (Unless i dont remember the armor stats of enemys that well, but any accessory early is good) having it on during expert hardmode is semi good, but by that time you should have better accessories to be used.