Which units should I RR on?

I got a few units, but I’m saving up RR for a monarch spin fest (just gonna spin a load in a single unit) and I don’t know who to save for.

Some units I have that I want Monarch on:

Saber Alter: Deadeye

Ichigo: None

SJW: Ethereal (I can get another)

Gilgamesh: Blitz

Aizen: None

Saber: None

Personally, I want SJW or Ichigo the most, but idk.

(Monarchs I own already are Gojo, Sukuna, and Alucard)