慢热病友高冷逗比
[màn rè bìng yŏu gāo lĕng dòu bĭ]
This username combines several traits. ‘Slow-burn friend with illness’ refers to someone who takes time to warm up socially but also identifies as a 'patient', possibly indicating a medical condition or simply being metaphorically sick in personality, such as slow and cool on the surface (cold), but can be funny and witty (joker) when you get close.