The way the Anger System would work is whenever a good player sees another good player die they gain anger from it or when they’re nearly killed and no its not a zenkai boost, we don’t need that, if the person is a saiyan of any sorts and dont have the super form upgraded, they can transform into super saiyan for a little bit. its similar to the god ritual, they have a timer and its weaker than the normal thing so like how goku did it on Namek. The anger can be triggered by evil people only and not by good players. Now onto SSJ Ikari [Rage]. It would work the same way as the whole super saiyan thing but you would have to have super form lvl 5 aka just have ssj2 unlocked, when the anger meter is up to max you can try to transform using grade 2 and 3 then you would eventually transform into SSJ Ikari, but you can edit the the percentage in the files of getting it, make it rare or common how ever you want it to work, It would work the same way as SSJ4 once you gain that form you can transform into it at will. It can also be triggered by a death of another good player.
I don’t know as that would be every tricky to Code even, which I would say it should be the way it is but you gain those forms as, I feel like you should be given a status like legendary but call Rage or something.
And it would have % chance to boost your power or gives you a higher percent chance if you see someone in your team Die.