At present, the main way to obtain interceptors requires killing level five guards, and in fact we can skip this step. On the Damage Guardian phase, there are strange purple machines that drop either an Inversion Mirror or an Echo Locator when destroyed. The blocked camp can be found through the echo, and the coordinates of a damaged guard gun and interceptor can be obtained by cracking the terminal.
There are many dissonant resonators and they are fragile. They are much faster than playing guards. The important thing is that you can easily hold the lenses.