http://www.pcgamer.com/an-infinite-damage-combo-has-been-discovered-in-divinity-original-sin-2/

One of the magical things about Divinity: Original Sin and now its sequel, Original Sin 2, is how complex and liberal their combat systems are. Whether by design or by accident, the glut of spell and physics interactions sometimes lets you get away with ridiculously OP moves. In the first game, for instance, players leveled up telekinesis, made absurdly heavy objects by stacking containers, and then dropped them on enemies for unreasonable amounts of damage. Original Sin 2 now has its own trick, courtesy of Ashandis on Reddit (and others), except this one appears to deal unlimited damage to a single enemy.

You can see the trick in action in the video above. How it works relies on several complimentary spells, as well as a quirk particular to undead characters: they take damage from healing spells.