User blog comment:Alejandro Magno/My number is larger than yours 2/@comment-80.98.179.160-20171226165925

(Cesillion!({X,X((X)X)X,X}&99 999!! 9999 999!! &&&&&&&&HH(999)(99999)))![999999]

Explanation: &99 999!! is a shorthand for &&&&&&&...&&&&& with 99999!! &s, where ! is factorial. To the left is an array with the right hand side (, which is 9999 999!! ) replaced with X. Then there are 8 &s, then HH(999)(99999). This is in parens, and that expression is tetrated to cesillion's factorial, which is $$10^{10^{1650}6}!$$. That expression is placed into parens and using HAN, is ![999999] placed after it.