After getting a few games in with Euripides, I thought I'd share few anecdotal opinions.
Holy haruspicy, seven 40mm 50mm models take up a lot of space! This crew is so starved for room to move around. I'm planning on downsizing my Gigants to Bultungin or - more likely - Lyssa, ASAP! It sounds WAY different on paper than it looks and plays on the map.
Gigants are strongly mediocre. They aren't bad, necessarily, they are just only really good at killing - and only within 8" - rather short for a dedicated ranged model. They could do some shenanigans with triggers for scheming or positioning or melee, but other Savages are better at those things anyway. I doubt I would consider taking them outside a Reckoning or kill comp.
Cyclops are amazing! They are absolutely an auto-include for Euripides to me. They scheme and poke with unavoidable damage but most importantly they can set up "bowling balls" for Euripides and really spam the map with ice pillars to support other Savages or control movement.
Primordial Magic is an unimposing powerhouse of efficiency. Its best ability is handing out incorporeal (often going to Thoon or Euripides) with a close second being the ability to clear markers around pillars. Don't underestimate the value of this little totem, it's fantastic.
Thoon seems lackluster save for his Frozen Trophy trigger. Since he's a beater and a tar pit damage sponge, I never found using his Arctic Pull or Hooked Chain was a better option than just swinging with Chain-Wrapped Fists to stack Shielded or do that sweet ice pillar bury with Frozen Trophy. I suspect he'd get more value in a crew with Geryon since they could beat and sponge while he does ice pillar things.
I haven't yet played with Bultungin, Lyssa or Geryon. However, I'll admit I'm most excited by Lyssa. When your map has 10+ ice pillars (my rookie number avg at turn 3), small incorporeal models just sound perfect. They seem to help stagger, lure and generally assist in making sure you keep control of the map. What do you guys think about Lyssa? Any experiences playing them?