Move aside. Rusty-Sama is here to help.
Basic monster line up you should be running is as follows:
3 x Algiedi
3 x Kaus
3 x Pollux
3 x Sombre (all mentioned above including this are mandatory)
Then your options are like add a Bear, TKRO, Veiler, Honest, etc. Just don't clog your monster line up. If you run any other Constellars than the ones I mentioned, you're wasting too much time on cards that are more susceptible to Maxx "C" or Veiler and also do not support you in playing the Rank 4 Engine, one of the best XYZ engines in the game. (Also Acubens is really not important. 500 boost just bc your monsters are now over 2000? Eh, rather go into Pleiades or anything else.)
Spells (What you should run):
3 x MST
2-3 x ROTA
3 x Tenki
1 x Raigeki
Then for the things you can choose to play: Book of Moon (Not the best card this format, but eh), Soul Charge, Dark Hole (This one I'm not entirely sure on. Board Nuke is nice, but in Constellar you have to maintain presence).
The cards you're currently running are too slow. Sure Star Cradle is an instant Rank 4/5, but you'd rather play cards that benefit off consistency and searching like your ROTA's and Tenki's. Lance would've been okay last year, but now it's not that good. Also, while duality provides this, it stops your plays for a turn, and YOUR XYZ PLAYS ARE CRUCIAL TO SURVIVE AT LEAST A TURN.
Traps (What you should run):
1 x Warning
1 x Bottomless
1 x Vanity's Emptiness
2-3 x Mind Crush
2-3 x Breakthrough Skill
Next is up to you, like Ring of Destruction, Compulse, Chaos Trap Holes, Torrential (so-so card this format but still gets the job done), Mirror Forces (recommended, tbh).
Constellar does not play like an OTK deck (for most of the time), so you should be playing traps that control your opponents plays (you should prefer "You can't play traps" like Vanity's, but anything that can stop your opponent works tbh). Don't play XYZ Reborn because it's too slow and can potentially be wasted on a blind MST or what have you.
Play a side. You need one unless you're playing Singles.
Extra:
2-3 x Pleiades (Your boss. YOU NEED MORE THAN ONE.)
1-2 x Omega
1 x M7
1 x Castel
1 x Abyss Dweller
1 x Exciton
1 x Tellarknight Ptolemaeus
1 x Stellarknight Constellar Diamond
Then it's up to you, though recommended ones are Durendal (which I see you're playing), Volcasaurus, Ragnazero, Diamond Crab King (one of your outs to Towers if you're not maining/siding Honest).
The Line up you play now is not fast enough to play through. Praesepe does nothing vs Construct or anything really. It's just a boost, and that's all it is. Tiras was good 1-2 years ago, and now it's just a so-so card. IDK how you get out Amaterasu, but not worth it. Pleiades is your most important card. Use it and abuse it, but be smart with how you use it.
tl;dr - Just read the ratios and you'll be fine.
