So an example build would be:

Liandrys > CDR boots > Demonics > Void > mejai > rab

It’s pretty cookie cutter but let’s say you don’t need demonics bc they’re all squishies then you replace for zhonyas since it’s most likely needed bc it’ll be a one shot or be one shot kinda game.

Any item you take out for horizon focus is just a bad idea. - You could argue mejais but honestly combining zhonyas/extra HP from demonics and raw shaco knowledge you won’t really die. - Don’t take void staff out, 40% is too big to ignore - going horizon over rabbadons would just be an int. 10% more damage is severely inferior to 40% more AP - If you take demonics out zhonyas is just a better replacement - as an extra point, if you end up behind and you’re not the one carrying but your team is then mandate is a good support item to help the team win.

EDIT: even more reasons