So I just downloaded Destiny 2 on xbox a few weeks ago and I’ve been rushing to get a few exotics before the update. I got the Polar Lance catalyst today and found a decent way to finish it.
Just a quick guide to completing the Perfect 5th catalyst challenge for Polar Lance. This requires enemies to die from burn damage, not the gun or explosion. It can be tricky. Some of the info on the internet was quite old so here goes:
Load up the lowest level Leviathan raid.
Enter inside until you reach Castellan. Lots of yellow bars you can mess with outside but I think the red bars inside are easier.
Follow the wall to the long downward staircase. Stop as soon as you see the Cabal spawn in. Let them stop moving and assume their places.
This is the important part. 3 headshots on a full health Cabal to begin charging the Lance.
Switch targets and make a 4th headshot on a seperate, full health Cabal. You are now fully charged.
While fully charged. Shoot the 2nd Cabal (the one you just shot) in the torso. This should knock his health down to a sliver where the fire damage will finish him.
There are about 8 or 10 Cabal here so you can do this pretty quick. To refresh the enemies I found running back out to the main entrance, then running back to the Castellan, to work. Should take about an hour or so depending on how good a shot you are. Lol!!