Scarlet Witch Hero Costume for Women

With a 42" bust, you're right that the XL chest measurement of 40" would be snug, since that's the garment's actual chest measurement rather than a body measurement allowance. The good news on the waist is that the XL's elastic waistband accommodates 33" to 41", so that piece has real flexibility built in. Since the shirt is a slim fit and the chest measurement is the garment itself, going 2" under on the chest may feel quite tight, so comparing how the costume is designed to fit against your comfort preference is the key call here.
(AI Generated Answer)

Yes the cape is included in the Women's Scarlet Witch Hero Costume and is more of a skirt and attaches to the shirt.

We have a full 30 day return policy, which means the package must be postmarked within 30 days of the order date.
You can start a return at: https://www.halloweencostumes.com/returns/

Hello, this Women's Scarlet Witch Hero Costume does run true to size.

Hello,
Please reference the size char on the Scarlet Witch Hero costume page.

Hello,
Please reference the size chart on the Scarlet Witch hero costume's page to see all the different measurement options.

Hello,
This Scarlet Witch Hero Costume includes the shirt, Pants, Skirt, and a Headband

Hello,
This costume includes a shirt, pants, skirt, and headband.

Hello,
There is now a size chart available! Another helpful tool can also be the costume sizing tips page.
https://support.halloweencostumes.com/kb/a63/sizing-for-costumes.aspx?ogid=66e8ed79-02d6-40d3-b76a-01c79650435d&DomainProjectID=13&ReturnUrl=https://www.halloweencostumes.com/child-spongebob-squarepants-costume.html