怪かい気き炎えん

• 大たい言げん壮そう語ご

  大言壮語 is a more formal, four-character compound meaning 'boasting' or 'grandiose talk', while 怪気炎 is more colloquial and often implies flamboyant exaggeration.

• ほら

  ほら is a casual noun for 'boasting' or 'tall tale', similar in meaning but less formal than 怪気炎.

• 怪かい気き炎えん

  Standard kanji form.

• 怪かい気き焔えん
  rarely-used kanji form

  Rarely used variant with 焔 instead of 炎.

• 快かい気き炎えん
  irregular kanji usage

  Irregular kanji usage; 快 is not standard for this word.

Compound of 怪 (strange, suspicious) + 気炎 (spirit, fervor). The exact origin is uncertain, but it likely arose as a vivid expression for overblown rhetoric.