For anyone out there struggling with their cat during pill session:

• wrap it in a towel, like a cat burrito;
• hold the pill with your thumb and index fingers and use the middle one to open the corner of the cat's mouth;
• it'll open its mouth very briefly, during that time you'll have to aim and let the pill go towards the back side of its tongue, near its throat

If you do it right, it'll swallow the pill reflexively.