I repeat: they wanted to have some of the memorable faces from the old guard of Fate-franchise Servants be more easily accessible. Hence Cu, Medea and Medusa being 3* Servants, who can be acquired (with enough time) from the Friend Point gacha, so the people who got into the franchise through Fate/Stay Night can reliably get a few familiar faces even if they don't spend money on SQ.

Or for the Fate/Zero fans, having Hundred-Personas and Diarmuid at 3* rarity.

Or for the Fate/Apocrypha crowd, Spartacus and Shakespeare being a 1* and a 2* respectively, or Avicebron (once he gets added) being a 3*.

Or for the Fate/Extra-series fans, Robin Hood and Lu Bu being 3* Servants, or Andersen being a 2* Caster.

Or for the Fate/Prototype-series fans, Serenity being a 3* Servant, and Arash being a 1* Servant.

... and then Aŋra Mainiiu is them just joking with making a super-secret 0* Servant in the Friend Point gacha that they basically never directly acknowledge in the official news section, but even he (and Euryale, a 3*) are familiar faces for Fate/Hollow Ataraxia fans.


It would be less enjoyable for the starting players if all of the familiar faces were kept in the gold-rarity tiers, meaning you absolutely needed to throw down Saint Quartz to be able to acquire any of the Servants you might have known from other Fate-franchise works.

Also, I'm pretty sure EMIYA and Gilgamesh generally outshine Cu in regards to popularity among F/SN male Servants, at least from what I recall of popularity polls I've seen.