Does anyone take Last Stand rune besides Karthus?

Tryndamere. Aatrox or Kled might be able to.

probably could, in matchups against certain things.

Same with

I take it on Alistar for all the wrong reasons.

I figure if I'm going down, I'm going down swinging. Maybe I'll get a few extra HP off their jungler or something and my ADC can pick up a kill at my expense.

But I'm bronze 5 so you probably shouldn't listen to me.

I also think it's valid on warwick.

I sometimes take it on for a final stand if I get caught out.

Last stand is very good on tanks/bruisers (who are constantly being focused) as well as a potential pick for DPS characters if they take some stray AOE (think an enemy ziggs throwing a Q, but missing the front line and bouncing towards the marksmen.)

It depends on what you think is a plausible situation. If you think you'll end up getting dropped low on health constantly, take it, otherwise the other options are probably better.

Yep, it‘s my favorite rune besides revitalize take it on every Toplaner/Jgl i play. Tryndamere, Jax, Nasus, Poppy, Tahm, Mordekaiser, Mundo and so on ...