Who wants to vote on who's worst case scenario semblance fail would be worst;
Russel's horrifically painful death upon waking up after taking enough critical damage
Or Cyan's holding her semblance long enough to suffocate herself and leave her a corpse encased in diamond-like glass?
Suffocation isn't nearly as bad as feeling all your nerve endings flare up, while simultaneously feeling any and all blisters, punctures and lacerations, to any type of burns all at once. The shock alone could kill him.
Suffocating sucks too, but she at least has the choice to turn off that semblance from what I understand; he isn't in control about what he is going to feel. Also with suffocation, you start to lose feeling. Not get a jolt of it. The loss of feeling gives the numbing pain... But two different types of it.
So really, only one of their semblances actually has a practical application. And that would be Cyan's.
No one wants to be stuck carrying the Gnome in a Left 4 Dead Run because it isn't just boring, but it becomes an escort. And that also just means you lose the use of not just one fighter, but two of them.
Russel's semblance leaves everyone in an objectively bad situation; but it does erase the fact it can be used for amusing or tense scenarios.