Board Thread:Questions and Answers/@comment-27733177-20180403184447/@comment-32271305-20180403190411

On that page you can find the "Leader" icon under any unit that you can use as leader.

Jiren is by far the best one, since he gives a +120% boost to all stats, which will go up to +150% with his future Dokkan Awakening.

The farmable PHY Ultra Instinct Goku is another unit that has a Leader Skill made specifically for that Category, as you can see on the Category's page: Universe Survival Saga. However, his boost is very low, so even AGL Caulifla's Leader Skill would be a much better choice!