Electrical – converting two lights from two switches to two lights from one switch

Based on your description, this would be the wiring setup. The yellow 'smudges' are wire nuts and the black ones are re-identified wires, grounds are not shown. Power coming in with /2, feeding down to the switch box with /3, and then going over to the secondary light with /2. I'm only showing this based on perhaps if you're trying to reuse existing wiring with a new setup as this is a working solution.

However, code-wise [ 404.2(C) ] this is no longer allowed. You are required to have a neutral splice at your switch box unless this lighting circuit will be located in a location where the switch does not serve a habitable room or bathroom, such as in an attic. So, as long as your lights aren't in a "habitable room or bathroom", you are able to go with this wiring diagram. [ 404.2(C)(4) ]

The other exception would be as long as you are able to get back to the box later on to add a neutral without disturbing the finish of the wall. [ 404.2(C)(2) ]

This is easier than it sounds

Basically, what you want here is an "open ended" multi-way switch, where each light is wired to a traveler.

In other words, you wire up a 3-way and a 4-way location to each other and to power as normal, but leave the load-side 3-way off. Instead, the two "travelers" from the load side of the 4-way location are turned into switched hots, one for each light.

The downside is that you'll need to turn this arrangement off at the breaker to change a lightbulb, unless you provide a separate disconnect switch somewhere in the line feed to this funky setup.