Keep it something that can't be overcome...
That would require actually sparing its use...
Rules of the Internet 45. Rule 45 is a lie. Check out my art if you notice.New forms would be fine if they had better reasons for them and I like the way Blue peogressed through the manga (though you could do a similar thing with 2 and 3 to flesh those out more).
If you're going to continue the story after the Boo arc and keep Goku as the lead, a new form is a good way to make him stronger than Gohan without lamely nerfing Gohan or just having Goku close that huge gap via basic training/having Gohan not train.
At this point, the power scaling has gotten to where there is basically no room to go up. Once Goku beats Jiren, that shows he's stronger than a god of destruction. After that, you have the angels, then Zeno. Unless they plan on revealing somebody even stronger than Zeno, Goku can only get so much stronger till there is no one else above him. The best plan in my opinion is just to start fresh with a new set of characters in the Dragon Ball world, but that's unlikely to happen.
Instead of progressively stronger enemies, just make enemies that have inventive abilities that challenge Goku and Co.'s abilities. I liked that about Hit and Zamasu. Even Toppo being able to use low-grade Hakai to destroy energy attacks was pretty neat.
Of course, all of those fights were resolved by just powering up and hitting them even harder...
edited 19th Feb '18 5:39:31 PM by Hobgoblin
Yeah, that was the problem with Hit. His ability is useless if you're not in nearly the same ballpark - if you are, that can be really cool (like the fight with Dypso, one of the highlights of the To P) but otherwise if you're weaker then he would win anyway and if you're stronger then it isn't going to make a difference.
The other problem is that for most characters all stats increase linearly - there are no Mighty Glaciers, Stone Walls, Fragile Speedsters. The strongest character will also be the fastest, etc. This was what was great about Magetta, he defied all of that.
"And when the last law was down and the Devil turned round on you, where would you hide, the laws all being flat?"Well, That was Toei as opposed to Toriyama.
That being said, the solution to an enemy having a special ability is usual to just be stronger than them anyway.
I do wish Toriyama had put a bit of a cap on that, but at the same time, some of the best battles the series has had were born out of that escalation.
One Strip! One Strip!What's wierd is that one of the fights in the Buu saga - with Yakon, I believe - was won by powering up when you could have written it totally differently. He can see in the pitch darkness of his planet, and when Goku went Super Saiyan to create light with the aura, Yakon ate it. So Goku just went Super Saiyan strongly enough that Yakon ate it all, and bloated up and died.
That's asinine. Why didn't they just have Goku use Kaiokenx 20 as the powerup and have him sense Yakon via ki? The entire point is for Vegeta to get jealous of Goku. Surely winning his fight with a much weaker transformation would make Vegeta more jealous, be a good callback to an ability that Goku didn't have much call for anymore, and also be a cool way to get around Yakon's power.
"And when the last law was down and the Devil turned round on you, where would you hide, the laws all being flat?"Goku didn't need to win the fight that way. He'd already shown that he could perfectly sense Yakon's movements via ki sensing. He just did that to show Yakon that he was way too powerful for the latter to eat all his energy.
One Strip! One Strip!

Honestly I'd just rather Dragonball just didn't introduce any new forms at all.
"And when the last law was down and the Devil turned round on you, where would you hide, the laws all being flat?"