is Ishtar worth NP2-ing?

It's up to you, if she's one of your favorite servant then go ahead. For me, i think that NP 1 Ishtar is enough and you even have Tesla NP 2 which does similiar job like her and NP 2 Tesla is really powerful.

Even before you got Ishtar, Tesla is more than enough to wreck thing so hard and you even have him at NP 2.
Now you got both monsters and i think you can cover another hole in your Chaldea.

Of course not, she's an AOE Archer and not even one of the best. You only roll for her because of the rinface.

I wouldn't spend over 1000 SQs on her just for NP2.

>NP2 Tesla

lol no, Tesla is the closest thing to Gilgamesh, Ishtar sucks in comparison.