Baffled by old age

[Quitti]

If Klaus the Mason is living creature, yes. And boosters will work. Luck scales don't affect it afaik, not sure about having luck from item/twist fate from bless.
T'ien Ch'i has several spells that reduce age over the eras, such as Thousand Year Ginseng and Internal Alchemy. Easiest way is still to give the leader an Elixir of Life or Boots of Youth. They stop getting the age afflictions completely, with the exception of magical aging such as Burden of Time.

[Thilock_Dominus]

Luck from spells or items do prevent a unit from afflictions, but I'm not sure how much % it is. Read it somewhere on the forum a while back.

[Anaconda]

Klaus is one of the MA Agathan heroes, very old and fragile.