ok if your main character is over level 15 and your friend comes over with his profile on a usb drive and needs ya help leveling simply do the following.
log your main in have your friend insert usb and sign his profile in after both characters are on have the higher level one do the following
open map scroll till your find the serphin island select recent activated gate and warp to it go into the cave leading to the boss battle ( dragon) have lower lever stand at least 3 feet from you set combo icon with he following Astral Lord Rally Souls whatever the skull that shoots arrows one is any skill that gives a boost to defense
doing this you can level any character from level 1 to maybe level 21 depending on the experience per kill
now if your friend has a weapon that gives him like +4.1% exp per kill then i would also suggest equipting one on the main character as well but have the lower lever use potions of the mentor it will give them +54.1% exp bonus per kill instead of just 4.1 or 50 [/size]
Complete the following Campaign modes as host to unlock the corresponding difficulty setting. It is possible to join open games of higher difficulties providing you are in the hosts set level range. You will not however be able to play those difficulties yourself as host until the requirements for that setting have been achieved. Note: the Bronze difficulty setting unlocks nothing.
Unlock Gold Difficulty: Complete any Silver Campaign as host.
Unlock Platinum Difficulty: Complete any Gold Campaign as host.
Unlock Niob Difficulty: Complete any Platinum Campaign as host.