Greater Mark of Detection
Source: Eberron: Forge of the Artificer p. 43
Prerequisite: 4th
You gain the following benefits.
Ability Score Increase. Increase one ability score of your choice by 1, to a maximum of 20.
Improved Intuition. When you use the Deductive Intuition benefit of your Mark of Detection feat, you can roll dice:1d6|noform|noparens|avg (1d6) instead of dice:1d4|noform|noparens|avg (1d4).
Shared Detection. When you use the Magical Detection benefit of your Mark of Detection feat to cast See Invisibility without a spell slot, you can choose one creature you can see within 30 feet of yourself. That creature also gains the benefits of the spell for its duration.