Grand Stairs With Two

At the first boss, you will need to have a burg in the group and a DPS
as the other. Fight the boss until the first fear debuff. Both players
will use fear potions. When the boss gets below half, the burg will
start a cj. Both players pick yellow for the DoT. It should die before
the second fear.

Now, head right and mez the two warg riders and
go on straight to the end of the path. Turn right and hug the right
side while running down and around. You will come across 8 warg riders,
and you will need to run past them. You need to get to Nardur and aggro
him. When he aggros, jump off the cliff and die. Be sure not to
realease until both of you are dead and the mobs are reset. This will
stop the hard mode timer, so you can go on without worrying about time.
After you are back at the start, run back to the bridge, it should be
down now...it was up when you passed it earlier. Mez the arrow mob.
Kill the other two. Then kill the archer. Follow the path north and
then after the corner to the left, doing the same thing to all of the
mobs along the way. When you get to Nardur's Station, there should just
be Hardur.

Have the other character jump on the railing to the
right and then on the torch. Engage Nardur from there. The burg should
be able to get behind him now. If he starts changing up on you, just be
patient, he should root the burg at some point allowing the other
character to attack. After you kill Nardur, return to where you killed
the first boss. The bridge will be down, so you can go north. Repeat
the process with the groups of 3 that you come across as you used
earlier. Move to the top of the stairs. You will find 3 ranged and 2
melee. You should be able to pull these one at a time. After that, go
up against the right wall all of the way to the throne room. Have the
other character jump on a chest and then on the middle of the throne.

It
should look like they are standing in air. The burg will stand up
against the back of the throne. After the other is in place, the burg
will come out and trigger Igash. When Igash comes, the burg needs to
run behind the throne again, and get right up against it. The two
archers will then start bugging. The burg will stay in that spot until
the archers reset. Have the other character attack Igash while this is
happening. Once the archers have reset, fight Igash. Kill him and
repeat.