Is this an intended feature?

Speederp

Using Eevee 143/191 im not able to evolve to tera sylveon. Additionally i was using eevee as well as Terapagos Ex against Uxie's Painfull memories. This attack puts 2 counters on all pokemon. Terapagos Ex has a "precursor" near the HP stating "As long as this pokemon is on your bench, prevents all damage done to this Pokemon by attacks (both yours and your opponents's)."

TechHog

Was the Eevee in the active spot?

Placing damage counters doesn't count as doing damage. That's intended.