Defeat enemies before the time runs out
Avoid flashy finishers (stun grabs) to save time
Perform combos with Atreus for greater damage (e.g. launch enemies in the air then shower them with arrows)
Kill enemies in quick succession. Enemies will resurrect if other enemies are still alive.
After defeating one enemy, you’ll have a few seconds window to finish off the next and so on
Wave 1: Heavy draugr x1, Draugrs (ranged x2)
Enemies will keep coming until you finish them in quick succession.
Damage enemies but don’t Kill them immediately. Once their HPs are low, try to group them up then finish them with a runic attack
Wave 2: Ogre, Revenant
Focus your attacks on the ogre first but don’t stun it. Next, attack the revenant and lower its hp as well. Next, you can stun the ogre if you still can, then mount it so you can use it to attack the revenant. Make sure that Atreus is firing his arrows consistently to un-phase the revenant and make it vulnerable to attacks.
Wave 3: Tatzelwurm x2, Wolves x3
These are all soft targets but the tatzelwurms will be quite hard to hit. Keep Atreus firing his arrows consistently then time your Runic attacks so you can hit multiple enemies at once.