Utiseta seems to be only for Supernatural Abilities from Major Virtues. So what other Abilities are there that they could use?
Poking through my books...
Cursing takes a whole season, so it's out. Same goes for Mythic Alchemy. Wouldn't make much sense to ritual-ize something so slow.
Healing is a potential candidate, and I guess putting a Group target on it or an Arcane Connection range could be useful. But apart from that, what could Utiseta do that would be interesting?
Maybe Utiseta healing can be performed without vis, but when used in such a way only gives a bonus to Recovery rolls instead of erasing wounds/fatigue completely.
Not sure where to go with Mythic Herbalism.
Whistle Up The Wind is pretty similar to what they've already got.
Control Fertility seems like a good option. Very appropriate to some titans, and there's lots of room for it to expand upwards. Create plants from nowhere, bless and blight vast areas, impregnate people with magical super-babies, or just make the effects last a long long time.
Comprehend Magic is also a possibility. Maybe for a Muspelli of Prometheus. It could give more information with Utisena, or give information about more things, or give information from farther away.
Dunno what to do with Banishing or Sihr.
Siren Song is a lot like Entrancement, so it'd be easy to integrate. Suitable flavour, too.
So yeah, I'd start with Control Fertility. Maybe go for Healing or Comprehend Magic if I wanted more options.