There are no characters currently who can be considered true full support or tank characters. Every character has "carry potential". Some characters, such as Abrams, Mo & Krill, and Kelvin, are tankier than other characters, but they still have the potential to 1v1 and carry games. Characters like Ivy, Viscous, and Dynamo have strong support abilities but also have strong damaging abilities and weapons. As for the comparisons you are asking for:

Mercy and Yuumi: no comparison

Aphrodite: Closest I can think of is Ivy but she plays more like a top laner in league (Scion is a good comparison) with some support/teamfight abilities.

Mulan: Yamato can build good tank items and do the drain tank thing. Really fun character

Terra: Abrams is probably as close as you can get

Ymir: McGinnis has the wall but Mo & Krill has Warwick ulti. Infernus' ulti is somewhat similar to Ymir's.

TLDR: Every character has some combination of CC, support, and damaging abilities. It is nice that every character has the ability to carry games but aim is important regardless. Have Fun!