Actually x2 Def Counter with 4+personnal equipements is better than x3 Def Counter with 1+personnal equipements since the Def given by the equipement count in the x2 or x3 calculation. If I look mine on DMM for example, at lvl80 she has 2970 Def (max ampie def, 100% normal affection) + 3245 with equipements. With her +20% def, she deals around 13600 counter damage. It's more than my Kerria's base normal damages.
Hyperloli is good too, but a bit less good I think. Her boss damage is not that good since a lot of 5* have the same thing for every battles and not only raid bosses ones. (and I'm not saying that because I prefer Mountain Lily since I prefer Hyperloli actually).

But I guess they are both really good event girls.