Amaranth braced himself. He opted for a stance that would make him difficult to move, and he converted some of the earth to cover his feet, to increase his chance of not moving. He moved his hands in front of his body, just in time for Oliver to crash into him. His hands caught most of the impact, taking the energy and storing it. It pushed him back a little, cutting at his feet with dragging through the ground, but he didn't move back to far.
When he had stopped moving, he released exactly back at Oliver what he had been dealt himself just then.