Off the top of my head, firstly when using archery if you are just far enough away ice elemental stay frozen and just take damage. Sometimes other npcs too. This is a common tactic players use.
I was training with wooden spear switched to repair hammer to repair the spear , I was two spaces away repairing my spear. Never seen before.
At southern pass players can become invincible if they do some sort of trick by waiting at the exit and then leaving and re entering .