Source: Eberron - Rising from the Last War

Prerequisite: No other dragonmark

You have manifested an aberrant dragonmark. Determine its appearance and the flaw associated with it. You gain the following benefits:

You also develop a random flaw from the Aberrant Dragonmark Flaws table.

Aberrant Dragonmark Flaws
d8 Flaw
1 Your mark is a source of constant physical pain.
2 Your mark whispers to you. Its meaning can be unclear.
3 When you're stressed, the mark hisses audibly.
4 The skin around the mark is burned, scaly, or withered.
5 Animals are uneasy around you.
6 You have a mood swing any time you use your mark.
7 Your looks change slightly whenever you use the mark.
8 You have horrific nightmares after you use your mark.

Option: Greater Aberrant Powers