Olaf the “Troll God”s Hammer

This plot device drives me nuts. Olaf is never referred to as a God in Triangle or in Selfless. The only time he’s referred to as a god is in the episode where they decide his hammer will work against Glory (“If you want to fight a god then use the weapon of a god”).

Meanwhile Spike can’t lift it in Blood Ties but Buffy can in The Gift. Buffy uses it to beat Glory to a pulp while Xander actually also takes multiple hits from it in Triangle (at least one directly to the head) so plot armour aside he should be dead as a doornail.

Why is Olaf referred to a god for just that one episode ? Why is the strength of this weapon so all over the place? what happened to it after season 5?