Constellars

In this deck, I essentially rely on xyz summoning Omega and preventing my opponent from destroying my monsters with spell and traps. Special summoning monsters using the effect of pollux and other constellars is also very important. however, I need help with a side deck because i want to start playing matches on DN and not only single matches.

Honestly, Constellars work great at 60 cards, as opposed to most other decks. Expand it a little, add some generic XYZ support and definately more Constellars. Your deck looks like the "Tribute Summon? What's that?" Constellar deck. Add more Level 5 Constellar Monsters. The Level 5's have their own XYZ in the archetype. Why do you have cards like Reinforcements, Big Bang Shot, Banisher of the Light and Card Trader? In my opinion, those are taking up room your XYZ support could have, if you do not expand the deck. Constellars are meant to XYZ instantly, so you don't really need to protect them if you have the right ones. Tutoring from Hand/Deck to field is their way to play, and there's one, when you summon it, you can tribute it to summon any other one from the graveyard (or hand? dont quote me on that, i havent used them consistently in a while.)

yeah dont add the level 5 constellars that is bad advice they arent good enough

Minus (-)
Monsters:
-3 acubens
-2 Alderbaran 
-1 Antares
-1 Rescha
-1 leonis

Spells:
-1 Lightning vortex
-1 big bang shot
-2 reload
-2 card trader
-1 Star hall

Traps: 
-1 of whatever the f-ck that first trap is

Extra:
-2 praesepe
-2 Omega  ( reason for this and above is one is enough )
-2 Hyades
- Number 142

Side deck:
- it all

Additions (+)
Monsters:
+2 Kaus
+1 Honest
+1 Fire Fist Bear

Spells:
+3 fire formation tenki
+2 Forbidden Lance
+2 Pot Of Duality

Traps:
+2 Fiendish Chain
+1 Solemn W and Solemn Judgement
+1 Call Of the Haunted

Extra deck:
+1 Pleiades
+1 M7
+1 Adreus 
+1 Gagaga Gunman
+1 Gaia Dragon, the thunder charger
+1 StarLiege Paladynamo 
+1 Shock master
+1 Black Corn
+1 Volcasaurus
+1 Tiras
+1 Wind-up Arsenal Zenmaioh

Sidedeck:
+3 Droll and Lock
+3 Maxx "C"
+3 Breakthrough Skill
+3 Mind drain
+3 Soul drain

Why so scared of backrow ._. What is this variant even? So I can fix.