Why most hierophant on Poeninja with unweavering stance use evasion bases?

For example there is this one https://poe.ninja/builds/settlersssf/character/938/sadsdafsadfsadf?type=exp&i=4&search=class%3DHierophant

He does have the keystone allocated and still uses gloves, boots and chest with a dex/int base, at first I though it was for spell suppression but neither his boots nor his gloves have the mod, is there anything I'm missing? I'm really lost.

This guy doesn't have unwavering stance, look at the keystones section. He uses timeless jewel to convert it to Corrupted Soul

it's transformed into corrupted soul by glorious vanity, to be able to benefit from both life leech and es leech at the same time.