Sunspot maintained his original powerset for roughly the first ten years of his existence, remaining a super strong but vulnerable individual throughout the entire "New Mutants" series. During the mid-1990s in "X-Force" his powers began to change, under writer Fabian Nicieza. Nicieza had the supervillain Gideon capture Roberto and subject him to experimentation where the limits of Roberto's power absorption were tested by feeding him immense amounts of solar power. Roberto was rescued by X-Force, but the overload had permanently altered his powers in such a way that he was now able to release concussive blasts of solar energy, with a considerable heat and light projection component; this experimentation also made him immune to all types of heat and fire. He can also now absorb other forms of energy; such as heat, light or even radiation in a manner similar to photo/radio- or thermokinesis. It was believed they do not power up his abilities but this was proven false. Sunspot also has some capacity to manipulate light based energy effects, but it remains a largely unexplored portent of his mutant power. It has been debated that Roberto would have reached these levels of his abilities of his own accord, and that Gideon's experimentation only increased his evolution process.