The ilClan is the Clan term for the "Clan of all Clans", determined by which Clan manages to capture the cradle of humanity: Terra. The senior Khan of the ilClan would then become ilKhan in perpetuity, and all future ilKhans would be chosen from the ilClan. In essence, the concept of ilClan determines which Clan the new First Lord of the resurrected Star League would descend from.
|“|| For the day will come and our kin will stand
On Terra's firm soil, ready to rebuild
The Star League with their hearts and hands.
But who shall lead? Upon whose shoulders
Will the burden lie? The answer is the test;
The test is the journey. Whichever Clan
Carves its way through the barbarians
To reach that fabled cradle of us all
Shall be the vehicle of the League's rebirth. Upon
The Star League throne shall sit that Clan's
Wisest Khan. So should it be -- So shall it be.
-- The Remembrance, Passage 72, Verse 22, Lines 14-24