Agile - why was the trait changed?

Now that poison does not wear off and can kill as well as agile is only 20% effective and i know a good healer/tank with high stats, Welcome back serpent to the soul grinding team that uses 2 serpents and 2 valks. Instead of killing a team and not losing a serpent i now only lose one or both but i can still clean up with valk. They may have changed the trait but they wont crush my soul farming team.