Ultimate Attack skills are obtained from four sources.
1. Creating your character.
Each character you create is given one Ultimate Attack skill by default: Full Power Energy Blast Volley.
2. Parallel Quests.
By chance, a skill can be dropped during a Parallel Quest or upon defeating a specific enemy in a Parallel Quest (including WARNING events).
Remember that you must clear the Parallel Quest to earn these drops.
When looking in the Parallel Quests menu, you can check the details of each Parallel Quest for which skill you have or have not obtained.
3. Masters.
Each master rewards you with an Ultimate Skill after you complete their final training exercise.
4. Wishes from the Dragon.
After getting the seven Dragon Balls and calling upon Shenron at the pedestal in Toki Toki City, you can wish for one Ultimate Attack.
There are two Ultimate Attack skills in total that can be obtained from this.
Note: Add-on content, either downloadable or as a pre-order bonus, is not needed to earn this achievement.