Spectre, Stage 2 (Ethereal Phasing)

You can cast the blink spell without expending a spell slot. Once you cast the spell using this boon a number of times equal to your Dexterity mod, you can’t do so again until you finish a long rest.

Flaw:
Hideous Appearance. Your true form is ghostly and haunting, whether due to your connection to death or your tenuous ties to material reality. Although your appearance isn’t necessarily scary, your spectral form seems unnatural to normal creatures who might believe you to be a ghost or other sort of spirit. You can manifest as the humanoid you once were, but doing so requires concentration on your part. Moments of stress, such as the following, reveal your hideous appearance.
• Using concentration, as if on or on a spell
• Becoming unconscious
• Entering hallowed ground
• Choosing to reveal your hideous appearance
• In events of extreme emotional or physical stress, the GM can call for a Constitution saving throw with a DC of their choosing to see if you reveal your hideous appearance.
When you reveal your hideous appearance, how viewers react is up to the GM. They might treat you as a ghost or another monster in disguise. Hostility and fear are likely reactions in these cases.