Of course you can't touch anyone.

With this idea I will make you stick alone with Makoto and Aoi.

This forbidden action could be linked to past physical abuse or maybe your oc has a phobia to touching.

Be aware if I decide that Ruruko would make a explosion happen then nobody could save you. However, I might not so that.

This could be maybe linked to being the ultimate public speaker or Something to do with speaking.

Or it could be linked to your oc being shy or use to be shy before opening up in the game. Or they could be a blabber mouth.

With this action I will make the reader know about the

(Major spoiler, it would literally ruin the whole anime series, so if you haven't finished it don't read this)

The reader would know that there was no real attacker and they could never tell anyone unless if someone knew sign language (let's just say Kyoko does since she is a detective)

Maybe your oc could have a deep connection with own of the participants of the game, and then being dead would trigger your forbidden action.

Be aware if that person died (you guys get to vote who) you will also die no matter what, this will not be like Kyoko's case.

I had this idea of one of the remnants being in the game. Or maybe someone else who also has the nickname of ultimate hope.

If they show despair it could reject everything about their title. Or it would be hard to do that forbidden action considering you're a remnant

Be aware if it's for remnant reasons people will accuse you since at the start everyone thought the remnants were behind this.

There was a theory of that being Ryota's and I found it a good idea.

This could be linked to a female family member being abused or getting bullied.

Be aware if you pick this then you would hang around Kyoko and you would defend all the girls you see no matter the what gender (if you have one) you are.

If your ultimate had something to do with attack or defends, or maybe you had a past or abuse weather it be you doing the abuse or not.

Be aware you would keep away from Juzo considering you never knew his forbidden action and all you known was he was the ultimate boxer.

This could be related to you being known to have a bad temper, or you don't see why swearing is a big deal.

Be aware this will make you talk a lot less and people will question you about it.

This could be if your oc is shy or if your oc has pride in them/her/his self.

This would make the reader quiet and just stand there and take the heat of people insulting them.

With the stress or the killing game (and if they have pride the sudden change in not standing up for yourself) would make them break down and cry often.

This will make the reader seem weak and a possible target for them to be "attacked"

This would do course be linked to a ultimate related to a musical instrument, or in Leon's case if you wanted to play to musical instrument.

This could work with anyone really.

Weather it be accidental or not, this would be physical injury, don't worry you can still be dead inside.

This could be linked to a clutz or if the reader self harmed themselves

This idea is from a Nagito story of "don't toy with my sanity" and basically the reader never showed emotions due to their past (which is unknown other then what they told Nagito, I won't leave any spoilers).

Basically the reader can't show emotions, on the outside anyway.

If they were to cry or smile or giggle, the poison would go off.