HT additional entry ticket + 6 party members is all you need.
OT: The leader needs to have the badge that you get when doing a PQ that requires the certificates, and you need Manon cry to transform into a dragon to get in.
the manon cry is the transformation quest. You need to transform into cornians in order to enter the cave. So you have to do it every time in order to ht.
The certificates are for mark of the squad quest. Which when compelted you receive a badge, which allows you to skip htpq. Therefore allowing you to solo ht provided that you have full party in your exped when entering ht cave.
@Masterobert I've tried using the HT additional ticket with 6 people in my expedition. When I use it, it only says that it only works if I have already HT already. Am I using the ticket wrong?[/quote]
Yea like he said you have to kill HT once and you will be able to use the coupon. However it is still nice to get the Squad Badge because maybe some day you want to take someone with you to HT and both of you don't own the badge, then you can't do HT with him.
Manon's cry and the other items are used to get inside the cave.
Certificates can come later. Just remember to activate the Hero's Mark quest (or whatever it's called) before you enter so you can see the badges.