I can advise the following:
Allegiance: Seraphon
- Constellation: Thunder Lizard
Leaders
Lord Kroak (320)
- Spell: Stellar Tempest
Engine of the Gods (260) (TQTH)
- Artefact: Cloak of Feathers
Skink Priest (70)
- General
- Command Trait: Master of Star Rituals
- Artefact: Fusil of Conflaguration
Saurus Astrolith Bearer (140)
Battleline
10 x Skinks (60)
- Meteoric Javelins Celestite Daggers & Star Bucklers
10 x Skinks (60)
- Meteoric Javelins Celestite Daggers & Star Bucklers
Stegadon (240)
- Weapon: Skystreak Bow
Units
3 x Kroxigor (140) (TQTH)
- 1x Moonhammers
Behemoths
Bastiladon (220) (TQTH)
- Weapon: Solar Engine
Bastiladon (220) (TQTH)
- Weapon: Solar Engine
Battalions
Thunderquake Temple-host (150)
Endless Spells / Terrain / CPs
Bound Geminids of Uhl-Gysh (70)
Balewind Vortex (40)
Total: 1990 / 2000
Extra Command Points: 1
Allies: 0 / 400
Wounds: 91
I don't know, which endless spell do you actually have, but if you don't have BWV, you can exchange it for burning head or just extra CP. If it is okay, to use your starpriest as priest, I would do so, if not, drop it for extra CP and make astrolith a general with 4+ CP gain trait.
The list is low on bodies and relies of removing enemy from the table by the end of turn 3. You also have a chance to summon saurus warriors. Feel free to experiment with the list, but general rules are:
1) You want a dual bastiladon in thunder lizard to deal lots of damage with high treat range;
2) To mitigate their slow movement, take battalion. Bonus CP and artefact are also very important;
3) Always take kroak, or at least slann, to generate lots of CP for dual shooting;
4) Always concerve CP for dual shooting. If you have excess CP, use it for +1 to-hit from priest. Thanks to the trait, he can do it once without spending a cp;
5) Give EotG or Skink Chief Cloak of feathers, so they can move 12, then run and still charge and all of this with fly. Very high threat range.
I wouldn't bother with saurus, since they are stricktly worse than thunder lizard. Yes, you can win with them and even go 3-0 in local meta. But since you asked for a competitive list, concentrate on thunder lizard and dual shooting bastiladons.
I also added astrolith and balewind. They both provide additional survivability (bastiladons save 2 additional wounds on average, and this can turn the tables) and makes kroak more dangerous (+1 to cast, +6 range).