You have to match each symbol on the chest to one of the totems by throwing the axe at it to spin it around. The one with the poison you throw the axe to spin the symbol then recall the axe and throw it at the thing that spits the poison so you can see what symbol it is. Just match up the symbols to the ones on the chest. They are not in order and if I remember right, one has two correct symbols but if you choose the wrong one you won’t be able to find the correct one on another because it has only one correct symbol.
Revenants are easy. Keep distance, have Atreus shoot it so it materializes, sprint up and smash it a few times, dodge away again and repeat. You can’t do continuous combos on them, just a few hits then back off.