Essence of Rage

You can drink this potion as a bonus action.
When you do, you enter a rage that lasts for
1 minute or until you're knocked unconscious.
This rage grants you the same effects as a
1st-level barbarian's class feature with the
following exception: if you end your turn and
you haven't attacked a hostile creature since
your last turn or taken damage since then, you
take 1d4 psychic damage and your rage does not
end. You can enter this rage even if you're
wearing heavy armor.