SP Goku Black YEL is a good Ranged Fighter, who at the time of his release owned one of the better Unique Abilities in the game: an extra 30% Damage to Saiyans and Hybrid Saiyans.
He's been power crept significantly at this point, and while he's still somewhat serviceable depending on the matchup and what Fighters the Player is missing, at this point he'll have to wait for either a Balance Change or a massive Boost to Future Teams.
An extra 30% Damage to Saiyans and Hybrid Saiyans is still a decent Unique Ability even if it pales in comparison to what some of the newer Fighters have access to Damage wise.
While SP Goku Black YEL is a good Blast Damage dealer, his Strike Attack and Defense lags behind considerably. This essentially means the opposing Team can optimize to play against him by utilizing Blast Tanks if they were actually worried about him.
Due to his Future Z-Ability and Tag, this is likely where he'd need to be used. Even then, Future is not in a great spot and neither is he.
The Special Move Damage here isn't very significant, but 18% Blast Attack still makes it the choice.
The following effects occur based on own remaining health: [Health is 50% or more] +50% to damage inflicted for 20 timer counts. [Health is below 50%] Restores own health by 20% and +35% to damage inflicted for 20 timer counts. Requirements: 15 timer counts must elapse.
+30% to damage inflicted against the following tags (cannot be cancelled): "Tag: Saiyan" "Tag: Hybrid Saiyan"
Deals major Impact damage. Inflicts enemy with Attribute Downgrade "+20% to Blast Damage Received" for 15 timer counts on hit.
Body Grows Familiar
+30% to own Vanishing Gauge Recovery for 15 timer counts. The following effects will also occur according to the number of timer counts elapsed since battle start: 15 counts: +20% to Blast damage inflicted for 15 timer counts. 25 counts: +20% to Blast damage inflicted for 15 timer counts and +25% to own Ki Recovery for 15 timer counts.