Champions with more than one build are the best-designed.
I mean champions that actually utilize it well, and not just something like, "Veigar is infinitely stacking, so I can build anything I want on him and still 1-shot people!" Something that can entirely change the way you play that champion, to fit and adapt to certain scenarios. I'll just give a few examples, starting with the most obviously forced one.
can use essentially the same abilities to do drastically different things when altered by his Blue and Red forms.
on Blue Kayn lets you just cuck absolutely anyone.

Red Kayn will let you dominate in 1v5's with all the mad sustain you get.

will let you just CC-lock people down for your team all day long like the obnoxious hob-knocker you are.
One guy, three scenarios. Brilliant!
Assassin.
Tank-shredding Duelist.
CC-lockdown Tank-thing.
Nice!
Assassin.
Duelist.
Tank.
Sweet!
Tank.
???????
1500-shield ultimate Ardent Shenser support!
I can think of many more
etc, but, yeah.
What champions do you appreciate for this reason, and what builds can they use?
So true^^
is a good example as we have
AD Sion
AP Sion
Bruiser Sion
and the rare lethality Sion
was one of the most versatile champs in terms of builds (on paper, at least).
while staying hard to kill
Support
AP utility
--- I mean Aatrox doesnt work at all with ap anymore?
has (had) two.

######There are more AP items I would like to try at some point like the Hextech actives, Shurelya's, and Lichbane
Tank items


is soo good
yea sure lol