>>4597317???
It's purple prose, basically.
Furigana are used to spell out how obscure kanji are pronounced. You can also use them to give context in other ways - e.g. a character in a scene says "he", but the name of the person they're talking about is also written, purely for the benefit of the reader.
Chuunis are known for throwing around obscure kanji everywhere, and/or abusing the "context" function of furigana, both in cheap attempts to sound deep (e.g. someone saying "my hunger" while meaning "my abyss").
In Fate/stay night, for instance, Saber's Noble Phantasm is written with kanji which would normally be pronounced "Shouri no Ken" (i.e. "Sword of Victory") and the phonetic spelling of "EkKUSUKyARIBA~". IIRC Gilgamesh also refers to himself with the archaic "ware" but pronounces it as the macho "ore".
