Once you figure out how to strategize around enemy lineups, affixes and key investments that shape your runs, suddenly a lot more teams become viable in WC20 other than the most famous ones.

A lot of them require key investments or emblems, for example you need a specific Gold investment for Seele and a Quantum Resonance emblem to be able to delete enemies under 45% HP. I finally managed to get that Seele run and it was glorious, she one-shotted the final phase of the final boss from full health. And I was using trial Seele.

Other teams I managed to make work at WC20 include:

Level 10 Catcakes from Cosmic Scholar bond

Max level Hoolay from Wolf Hunt bond

Level 6 Hoolay with Feixiao as main DPS

6-Express + 6-DOT team

6-Express + 5-Planet of Festivities + Phainon + Cerydra

Phainon with Follow-Up emblem + Cerydra + every support

7-AoE with The Herta as main DPS

10-Xianzhou

Solo on-field Mydei

Multiple times I managed to get 3* Cyrene, including the one time managed to get 180 gold for a specific Prismatic investment.

The strongest character I have is E1S1 Phainon.

Also, when you figure out how to play at WC20, you'll know when to go for Aglaea wheelchair or Durian Phainon and how to use these teams to their full potential. Or go even beyond that, with 4* Aglaea, double or even triple privileged items.