How to use items in Dragonball Z Xenoverse

you just need to fight other "time patrol". they show up randomly during missions.

The best way to collect the 7 DB is to do the mission 02. After you've defetead the 3 first fighters (krilin, yamsha, tenshinha), one npc can appear near the temple. just challenge him and try to finish him with a final attack, it seems to boost the chance to drop a DB.

to know if you've got a dragon ball after the fight you should have a message saying that you've got a new "key object". if not, you can select "retry" on the menu to be faster.

Of course after you've succesfully got your DB you need to finish the mission and if you fail... no more DB for you this round.

You don't need to do another caracter to collect them again, you can do it as much as you like with your main caracter.

There are only 55 Parallel Quests, and you can find the Optional Objectives here:

http://shinigaming.com/2015/03/04/dragon-ball-xenoverse-parallel-quest-guide/

List of all Parallel quests and their hidden conditions:

#0 – “Parallel Quest Tutorial”:

Hidden condition 1: Defeat all Saibamen
Hidden condition 2: Defeat Raditz
#1 – “World tournament Tag Team”:

Hidden condition 1: < 5 min
Hidden condition 2: Defeat Piccolo
#2 – “Prepare for the Attack of the Saiyans!”:

Hidden condition 1: < 5 min
Hidden condition 2: Defeat Goku
#3 – “Saiyan Blood”:

Hidden Condition 1: Raditz Health > 50%
Hidden Condition 2: Defeat Gohan
#4 – “Saibamen’s Revenge”:

Hidden Condition 1: < 5 min
Hidden Condition 2: Defeat Nappa
#5 – “Attack of the Saiyans”:

Hidden Condition 1: No Saibamen Escape
Hidden Condition 2: Defeat Revived Saiyans
#6 – “Invade Earth”:

Hidden Condition 1: Nappa Survives
Hidden Condition 2: Defeat Revived Goku
#7 – “Burst Open and Mix!”:

Hidden Condition 1: < 10 min
Hidden Condition 2: Defeat Time Patroller in Training
#8 – “Namekian Dragon Balls”:

Hidden Condition 1: Clear by beating Guldo
Hidden Condition 2: Get 7 Dragon Balls
#9 – “Saiyan Pride”:

Hidden Condition 1: Vegeta’s health > 50 %
Hidden Condition 2: Defeat Revived Goku
#10 – “Defeat Frieza’s Army”:

Hidden Condition 1: < 10 min
Hidden Condition 2: Defeat Ginyu, Burter, Jeice
#11 – “Force Entrance Exam”:

Hidden Condition 1: Guldo’s Health > 50%
Hidden Condition 2: Defeat Ginyu
#12 – “Fierce Battle! Ginyu Force”:

Hidden Condition 1: < 5 min
Hidden Condition 2: Defeat Frieza
#13 – “Tri-Race Coop”:

Hidden Condition 1: < 5 min
Hidden Condition 2: Defeat Frieza and revived Enemies
#14 – “Legendary Super Saiyan”:

Hidden Condition 1: Defeat Krillin before Goku
Hidden Condition 2: Defeat Super Saiyan Goku
#15 – “Explosion of Namek”:

Hidden Condition 1: < 3 min
Hidden Condition 2: Defeat Time Patroller in Training
#16 – “Super Saiyan Legend”:

Hidden Condition 1: Befriend Vegeta and clear with him alive
Hidden Condition 2: Defeat Super Saiyan Vegeta
#17 – “Challenge Hercule”:

Hidden Condition 1: Hercule’s Health > 50 %
Hidden Condition 2: Defeat Revived Vegeta
#18 – “Return of Ginyu Force!”:

Hidden Condition 1: < 5 min
Hidden condition 2: Defeat Frieza
#19 – “Let’s Train”:

Hidden Condition 1: Clear with Vegeta and Gohan Transformed
Hidden Condition 2: Defeat Revived Gohan
#20 – “Multiple Cell Jr. Hunt”:

Hidden Condition 1: < 5 min
Hidden Condition 2: Defeat Cell
#21 – “The Cell Games Begin”:

Hidden Condition 1: Defeat Piccolo and Goku before Gohan
Hidden Condition 2: Win without defeating Cell
#22 – “Earth in Danger”:

Hidden Condition 1: Defeat all enemies
Hidden Condition 2: Defeat all revived enemies
#23 – “Clash! Perfect Cell”:

Hidden Condition 1: < 3 min
Hidden Condition 2: Defeat Revived Cell
#24 – “Power Teams”:

Hidden Condition 1: < 10 min
Hidden Condition 2: Defeat Revived Gohan and Cell
#25 – “17 and 18 of the Official History”:

Hidden Condition 1: Vegeta and Piccolo Survive
Hidden Condition 2: Defeat Revived #17 and #18
#26 – “Warrior’s annihilation – Future Chapters”:

Hidden Condition 1: #17 and #18 survive
Hidden Condition 2: Defeat Trunks
#27 – “Artifical Warriors”:

Hidden Condition 1: Beat all Cell Juniors
Hidden Condition 2: Defeat Cell and revived #17 and #18
#28 – “Take back the Dragon Balls”:

Hidden Condition 1: Beat all Cell Juniors
Hidden Condition 2: Get 7 Dragon Balls
#29 – “2nd World Tournament Tag Team”:

Hidden Condition 1: < 5 min
Hidden Condition 2: Defeat all enemies
#30 – “Great Saiyaman is here”:

Hidden Condition 1: Great Saiyaman survive
Hidden Condition 2: Defeat Revived Frieza and Cell
#31 – “Majin Chaos”:

Hidden Condition 1: < 10 min
Hidden Condition 2: Defeat Buu
#32 – “Super Saiyan Bargain Sale”:

Hidden Condition 1: < 5 min
Hidden Condition 2: Defeat Super Saiyan 3 Goku
#33 – “Namek Berserker”:

Hidden Condition 1: < 5 min
Hidden Condition 2: Defeat Revived Piccolo
#34 – “Majin Revival”:

Hidden Condition 1: Buu’s Health > 50%
Hidden Condition 2: Defeat Revived Hercule
#35 – “Tag with Gotenks”:

Hidden Condition 1: < 5 min
Hidden Condition 2: Defeat Ultimate Gohan
#36 – “Majin Banquet”:

Hidden Condition 1: < 5 min
Hidden Condition 2: Defeat Hercule and revived Buu
#37 – “Potara Warrior”:

Hidden Condition 1: Super Buu’s Health > 50%
Hidden Condition 2: Defeat Super Vegito
#38 – “Blast the Super Spirit Bomb”:

Hidden Condition 1: Buu Survive
Hidden Condition 2: Defeat Revived Kid Buu
#39 – “Cell Games Continued”:

Hidden Condition 1: Defeat Videl and Piccolo before Gohan
Hidden Condition 2: Win without Defeating Cell
#40 – “Stop Beerus’ Destruction”:

Hidden Condition 1: Clear without any ally defeated
Hidden Condition 2: Defeat Whis
#41 – “Frieza’s Nightmare Returns”:

Hidden Condition 1: Defeat Gotenks before Vegito
Hidden Condition 2: Defeat Super Vegito and Super Saiyan 3 Gotenks
#42 – “Power of a Super Saiyan God”:

Hidden Condition 1: < 3 min
Hidden Condition 2: Defeat Revived Goku
# 43 – “Old Rivals and Dragon Balls”:

Hidden Condition 1: Clear by defeating three enemies
Hidden Condition 2: Get 7 Dragon Balls
#44 – “God of Destruction and his Master”:

Hidden Condition 1: < 5 min
Hidden Condition 2: Defeat revived Beerus
#45 – “Saiyan Battle”:

Hidden Condition 1: < 5 min
Hidden Condition 2: Defeat Goku and revived Gohan and Vegeta
#46 – “Evil seeks Dragon Balls yet again!”:

Hidden Condition 1: Clear by defeating all enemies
Hidden Condition 2: Get 7 Dragon Balls
#47 – “Super-Super Ultimate series of battles!”:

Hidden Condition 1: < 10 min
Hidden Condition 2: Defeat Vegito and Gotenks
#48 – “Gathering of the Great Evil Alliance”:

Hidden Condition 1: < 10 min
Hidden Condition 2: Defeat revived Frieza, Cell and Kid Buu
#49 – “Saiyan Revolt”:

Hidden Condition 1: Raditz and Nappa survive
Hidden Condition 2: Defeat Vegito
#50 – “Parent and Child”:

Hidden Condition 1: < 10 min
Hidden Condition 2: Defeat Burdock, Raditz and Goku
#51 – “Heated Furious Ultimate Battle”:

Hidden Condition 1: Clear with revived Goku surviving
Hidden Condition 2: Defeat revived Broly
# 52 – “Great Ape Festival”:

Hidden Condition 1: < 10 min
Hidden Condition 2: Defeat the Time Patroller in training
#53 – “Dangerous Duo! Warriors never rest”:

Hidden Condition 1: Defeat Broly with Gohan surviving
Hidden Condition 2: Get 7 Dragon Balls
# 54 – “Saiyan Warriors”:

Hidden Condition 1: < 10 min
Hidden Condition 2: Defeat all revived enemies
#55 – “Power Berserkers”:

Hidden Condition 1: < 10 min
Hidden Condition 2: Defeat Gohan, Broly and Bardock