I currently have 1 and 3 (failed getting 2 after re-spinnig the roullette 4 times).
While that combination is quite deadly in itself, it's with other P5 costumed characters(other than Colossus) that it becomes balance-breaking.
For example, getting Cyclop's buff, you get the arc-reactor charged Phoenix Flare to always hit and crit. Ouch. More or less the same with Dark Phoenix, you sacrifice crit but instead get it to avoid most avoidance effects.
With Emma, you either wait for her buff or just buff up using Unlock potential, and again, a 1-3 combo hits hard.
Even if you don't have P5 costumes, it becomes deadly with Emma's Unlock potential along with:
1. Gambit's Royal Flush: decrease defense.
2. Thing/Hulk/Collossus/Luke/Spiderwoman etc: reduced chance to evade that massive attack
So yeah, I'm currently using 1-3, Emma and Gambit/Cyclops P5, and when the stars align just right and my hero gets Cyclops buff, Unlock potential, Arc reactor and Phoenix Flare, it has a good chance of eliminating all 3, or at least one.
The obvious counter is to have Emma (diamond body, can often withstand the hit), Kitty (begins phased with alt), and equipping the hero with the Mutant's End, but it would be counter productive to have all that prepared just for the off-chance you meet this combo.