Dragon Ball Xenoverse 2 raises the bar of difficulty in terms of Expert Missions. The most difficult quest by far is Expert Mission 15: Extreme Malice. Here's a guide on the skill set you need to beat Expert Mission 15: Extreme Malice on Dragon Ball Xenoverse 2 and obtain Z Rank.
Dragon Ball Xenoverse 2 - Super Soul
During boss fight, you will need your teammates to serve as distractions. As they head to head against the opponent, they will most likely lose much of their health points than you. Hence, using Elder Kai's Super Soul "Hmm Hm Hmm! Hmm Hm!" is highly recommended here. Couple it with a pose and awoken skill to regenerate health for the entire team.
On the other hand, you can also use Towa's Energy Zone to heal your team members. However, it only releases a small amount of healing aoe, around 15 percent, which makes it undependable. Take note of the downsides-it uses three bars of Ki and more time to cast, not to mention you cannot move while using it.
Dragon Ball Xenoverse 2 - Super Attacks
In terms of Super Attacks, employ Rise to Action, Big Bang Kamehameha, fighting pose and maximum charge. Rise to Action is best when you have stamina problems because it will give you two bars of stamina for one bar of Ki. Meanwhile, any fighting pose technique should get you through the game.
Vanishing Ball and Perfect Shot are two recommended Super Attacks. Both are good at firing swiftly, plus the impressive damage it does, which is 75 percent of one Big Bang Kamehameha. Saiyan's Big Bang Kamehameha makes good damage with its medium range. It is important to remember that awoken skill should be used along with the reinforcement skill so Super Soul gets unlocked. If you can do SSJ, warp at their back to score 6.5k~ of damage per Ki bar.
Dragon Ball Xenoverse 2 - Ultimate Attacks
In terms of Ultimate Attacks, it is highly recommend to use at least one, preferably Weekend or Final/Perfect/Super Kamehameha. Weekend requires three bars of Ki, while Final Kamehameha requires five bars of Ki. However, it's unwise to do a series of Ultimate Attacks because they will exhaust charge ability to fill up your Ki. Use melee attacks, instead.
The boss enemy uses Blue Balls to hit you. Be careful because this makes great damage, and if multiple balls hit you that means greater damage. Apart from that, these are very dangerous, most especially when you are at close range with your enemy because Blue Balls vanish and will pop out everywhere without you noticing it. Prevent one of your teammates to hover around you at any time because the balls might hit both of you. The key here is to scatter.
Dragon Ball Xenoverse 2 - Evasive Attacks
In terms of Evasive Attacks, it is highly recommended to use the Vanisher Guard because the duration is longer, and it can be activated at any time even if you are being attacked.
Dragon Ball Xenoverse 2 is now available on PlayStation, Xbox One and Windows PC worldwide.