I disagree.
Obviously, most everyone builds
for tank supports,
for poke supports, and
for sustain supports (with a spare few exceptions here and there).
Well, I find that some supports lacking in some area with their standard item can make up for it with Ancient coin.
usually builds
, but I find that it's much easier and more effective to play him as an offtank. Unlike
or
, he doesn't have the insane tankiness to waddle into lane and last hit minions like they do without risking an opportunity attack from the enemy support and ADC and he can't punish them for doing so. But with
, he gets much greater mana regen and can actually use his Q frequently since he has the mana to do so. And when he needs to head out in to lane to pick up the coins, it's not hard since he just needs to get somewhat close to them rather than getting right up in its face and hitting it.
In another scenario,
's eaten a string of nerfs that's effectively been demolishing her ability to hurt people. While this is good for game balance so she stops going Mid, Top, and ADC, it's also struck down her ability to support since she can't poke very well. It's now become necessary for her to use E + Q in order to get the most out of a poke and that costs too much mana in the long run.
helps her make up for this by granting the mana regeneration to use her abilities. While she still lacks the actual sustain usually associated with an Ancient Coin support, she can still whittle down her enemies and turn engages into a bad idea by dosing her ADC with steroids.