Krillin flies in front of the sun and uses the Solar Flare, but as he does he uses much more energy and strengthens the blinding effect. This technique is so powerful that it is still able to blind opponents even if their eyes are closed, and the victim will also be unable to sense the user's ki, leaving them completely blind and defenseless. However, sunglasses can still negate the intense rays. According to Android 18, the technique cannot be used over and over as it apparently uses a lot of energy, and it should only be used as a surprise attack.
Krillin used this technique during his brief sparring match with Gohan using the Tournament of Power's ring-out rule. Krillin flies in front of the sun and uses Solar Flare x100, blinding Gohan from seeing and sensing Krillin's ki. Krillin takes the opportunity to knock Gohan out, forcing him to use Flight, thus making him lose the match due to the rules. Gohan was very impressed by the technique and notes Krillin's skill and experience, also noting he will do fine in the tournament.
During Krillin's second sparring match with Goku, 18 was worried about Krillin's stamina due to using the technique on Gohan earlier, as it uses a lot of energy and she was worried that Krillin may be too tired to keep fighting.