From my comic, That Stick Figure Isekai.
The Red Giant (Quincy Q. Quinn). He be a swashbuckling irish superhero with a pogo telescope bow-staff. His laughter can break through any vacuum. Meaning you won't HEAR anything in space.... because Quincy is too busy making them BLEED.
I plan on having him get a little personal with his quips (to the point where villains cry). So he's basically making them wish they were deaf... :v
He moves around like a monkey and had a lisp in his previous world before he became a stick figure. He was also 5'0 in his previous life contrary to what the art has you believe.... his stick figure is bigger than him.
The Red Giantess has the best design so far lol (until you meet her sister... then that's up to debate). We wanted to do something where she believes she's the center of the multiverse. She wants EVERYONE to know her name, but she does things in such a risky fashion that she constantly puts herself in danger. She's like a literal red giant where she can burst any moment.
Tizoc
This guy's an Aztec warrior that can summon a spirit. The Jojo posing is because his stick figure body is actually because he's a supermodel who threw his life away. His body is subconsciously making those poses :v :v
D & Nancy:
D tries to be "anime" and tries to prove himself to his best friend, Naota.
Nancy is a cold blooded assassin who'll do anything to achieve her task. They love each other lol.
To answer your question about how I make characters cool... I focus on their concepts and just let my artist have all the fun. What's a cool concept and how does it fit the plot thematically? Characters are chess pieces.
I will say their vulnerabilities is what makes them cooler. Of course, not all characters should HAVE flaws, but it is a good spice. That Stick Figure Isekai allows me to have these characters shine through stick figure bodies and see how far they're willing to push themselves.