The ability to possess innate knowledge of how to make the best of one's abilities. Technique of Efficacy Manipulation. Variation of Intuitive Aptitude.

Also Called

  • Effectiveness Intuition/Perception/Sense
  • Efficacy Perception/Sense
  • Efficient Mind


The user possesses great, if not natural, knowledge of how to make the best of themselves. This includes how to make the best of their abilities, maximize the situation to full effect, making use of what they have available to them, utilizing their maximum potential, how to get the best results and how to push themselves to get the best of their abilities. Thus allowing them to automatically; plan, analyze, and take action with absolute efficiency.




  • May not be able to sense certain ways of making the best of oneself.
  • May not understand some of the how-tos in making the best of themselves.

Known Users

  • Index Librorum Prohibitorum (A Certain Magical Index)
  • Marcus Ayers (Alphas)
  • Claire Stanfield (Baccano)
  • Kiriyama Kazuo (Battle Royale)
  • Contractors (Darker than Black)
  • Midnighter (DC Comics/Wildstorm)
  • Slade Wilson/Deathstroke (DC Comics)
  • Tywin Lannister (Game of Thrones)
  • Kazuya Souma (How a Realist Hero Rebuilt the Kingdom)
  • Various Characters (Kingdom)
    • Ou Sen
    • Ri Boku
    • Shou Hei Kun
  • Edward "Eddie" Morra (Limitless)
  • Callisto (Marvel Comics)
  • Kraven the Hunter (Marvel Comics)
  • Steve Rogers/Captain America (Marvel Comics)
  • Teon Macik/Primal (Marvel Comics)
  • Renner Theiere Chardelon Ryle Vaiself (Overlord)
  • Sakamoto (Sakamoto desu ga?)
  • Arcturus Mengsk (Starcraft)
  • Gems (Steven Universe)
  • Rimururu Tempest (That Time I Got Reincarnated As a Slime); via Great Sage
  • Tatsuya Shiba (The Irregular at Magic High School)
  • Amakusa Shirou Tokisada (TYPE-MOON); via Revelation
  • Jeanne d'Arc (TYPE-MOON); via Revelation
  • Solomon (TYPE-MOON); via Revelation
  • Adrian Veidt/Ozymandias (Watchmen)
  • Users of the Answer Talker Ability (Zatch Bell!)
    • Dufort (Zatch Bell!)
    • Kiyo Takamine (Zatch Bell)

Known Powers

Known Objects

  • NZT (Limitless)
  • Calypso Serum (Marvel Comics)
  • Super-Soldier Serum (Marvel Comics)
  • Processor Suit (To aru Majutsu no Index)
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