"Slaying" requires timing; use her EX Special Attack at the peak of a chain reaction for maximum visual impact. The Evolution of Internet Slang
The addition of "broken holes" and "extra hot" likely stems from a mix of gamer jargon: i a burnice special for her broken holes slayed extra hot
Stack Fire DMG and Anomaly Proficiency to ensure the "Burn" status is always active. "Slaying" requires timing; use her EX Special Attack