When you find the 2nd Tombstones in Rohan, if you are a tanker, get some Healer with good Barrier, tell him to barrier you at the bridge , after that , just go kamikaze inside , get off mount and double click the tomb ( then get out if you can lol ) .

If you are not , you have to fight your way thru . Its kinda tough since the mobs there are around lvl 40(Rohan powerleveling) i remembered.

For the 1st 3 caves Crystal Quarry , Akhma Cave and Lauke Monastery , just tell your ppl get there , at least 1 person each cave so they can summon you right to the chest . You will save your time travelling over the whole map .

At the last cave Caronia's Tomb , better have a party and fight your way thru , the Eyes are range attack mobs , they are pretty annoying .

When you fight the big boss , just need a tanker and a healer with good barrier . Healer can spam barrier the tanker so he can taunt and tank the boss .

As long as the boss agro the tanker only , party members wont get aoe from him . Also you should get a dmg dealer or someone else who can clear the trashes around for tanker and protect the healer . If the tanker lost the boss's agro , boss will aoe the whole team and obviously , healer will die.