There is a reason why the term limit is put on the presidency and not the National Assembly. A term limit is put to prevent self-perpetuating rule by not occupying the office of president for more than two terms.
Democracy allows the seeking of the mandate of executive power more than a hundred times but to occupy it only twice to prevent the presidency from being a monarch.
A National Assembly member can never have the power of a monarch but the presidency is an embodiment of the power of a monarch. Democracy seeks to limit that power and prevent a monarchy from emerging by reducing the term to two. Nobody prevents a former president from standing and becoming a National Assembly member more than a hundred times if he or she so desires.