Nibiru, the Primal Being, and a lesson on self-restraint

Nibiru, the Primal Being Level 11 LIGHT Rock During the Main Phase, if your opponent Normal or Special Summoned 5 or more monsters this turn (Quick Effect): You can Tribute as many face-up monsters on the field as possible, and if you do, Special Summon this card from your hand, then Special Summon 1 "Primal Being Token" (Rock/LIGHT/Level 11/ATK ?/DEF ?) to your opponent's field. (This Token's ATK/DEF become the combined original ATK/DEF of the Tributed monsters.) You can only use this effect of "Nibiru, the Primal Being" once per turn. ATK 3000 | DEF 600

Quite frankly, Nibiru is one of the main factors that limits our success just because of how much it excels at stopping combo decks that cannot prevent or recover from it.

We are a prime example of that, as we're only able to stop Nibiru if we manage to get Arvata on the field before the 5th summon. That does happen, but not consistently enough, as there are many lines that cannot do it.

We don't have many ways to recover from it either, as usually we use Sacred Fire King Garunix's effect before Nibiru even has a chance to hit, and everything else doesn't generate enough material to recover. Thus, it quickly becomes a priority to ensure you can play under the 5 summon threshold as much as possible.

All the combos in the Combos section have a note about Nibiru, telling you whether that line can stop it or if it plays into it. Make sure to remember that as it can help you decide which setup is best for your current situation.

One thing you should learn to do immediately is avoid activating unnecessary effects that summon monsters.

A lot of times during your combo you might destroy an Arvata or a Kirin, and their effects will come up, but you don't need the monster they summon to finish your endboard. Generally, it's best to not activate those effects to keep your summon count low, even if it feels wasteful.

Also, avoid extending when it doesn't make sense to do so. If you think you can beat your opponent with an Arvata on the field and 2 Level 8s for Hyang, plus the non-engine in your hand, then there's very little reason to go into Princess or Amblowhale.

As you gain more and more experience with the deck, you'll be able to tell at a glance what lines your opening hand can do, and coupled with meta and matchup knowledge, you should be able to tell how low to the ground you can play and still have a chance at beating your opponent.

That said, there will be matches where you just have to gamble. You might have zero non-engine in hand, and you're sure a Hyang isn't enough to win. In that case, go past that 5 summon threshold and try to do your best - sometimes it'll work out, sometimes it will not.

Overall, try to be mindful of Nibiru and keep your boards as minimal as you need, and you should be fine.