Dropping some of my thoughts here. 

Highfalutin - Meaning "(especially of speech, writing, or ideas) pompous or pretentious." Pride. This person is so wrapped up in themselves and impressing others that it is their own source of power. They get stronger/faster/smarter or have another ability that grows the more highly they think of themselves, but the downfall is that if their confidence is broken, then their abilities decrease proportionally.

This is my favorite, and I love the synergy with the complement-based power already suggested. With every compliment their head (and power) would [i]swell[/i]. 

Extra: Devil's Pride. The first sinner, Lucifer, fell for his pride and those who share his ambition to overthrow God are able to call upon his powers. Devilry will be afoot. (because they refuse to learn the metric system. Also probably invented the imperial system.)

Comb - in particular, "to search carefully and systematically", also "to untangle or arrange (the hair) by drawing a comb through it." Their power is to find things they are looking for and to make sense of complicated things through careful study. Think Sherlock Holms. Could be a hair stylist or a barber for extra laughs.

Kettle - Either "a container or device in which water is boiled, having a lid, spout, and handle." Easy, steam/water powers with a signature 'waterlock' that puts the target in a container of water/steam. 

Sisterhood - Kinda tough. Major Sex Appeal? Hah.

Hornsnake - Simple. Danger noodle person or danger noodle whisperer. Vanilla but workable. Sadly, hornsakes are specifically a harmless snake so um oof. If stretched, I could take it to mean a 'horned snake', which is a type of desert viper. Or, really far, a Basilisk or Cockatrice, both often depicted with horns.