Final 6 concepts

GENERAL
- The more monsters you have, the more important equips are. The more equips you have, the more important monsters are (especially Tier 2 dragons).
- The value of Widespread Ruin increases exponentially: 3 is a lot better than 2, which is moderately better than 1, which is slightly better than 0.
- The better your deck is at making Gate Guardian beaters (3800 THTD or MBD), the more important Dragon Capture Jar is.
- Fields are much less useful if you have Megamorph or MBD, but they are still worth keeping in for the final 4 unless you have an especially strong 15-card race deck.
- Dark Hole is a lot better than Raigeki for Seto 3 and DarkNite, but Raigeki is a lot better than Dark Hole on Heishin and Nitemare if you use it properly (usually involves setting turn 2).

SEBEK
- Any deck that can semi-consistently make a 3300 will have a very high win rate; the effect of additional consistency is minimal. This is because falling behind against Sebek rarely results in a loss -- he plays lots of harmless backrows and Shields, and he has nothing to stop Raigeki.

NEKU
- Most straightforward duel of all -- MBD/SK are best, equips are next-best (nearly as good as single monsters with very high D/T counts), Umi/Mountain are next-best, random fields are next-best.

HEISHIN
- It's all about making Gate Guardian beaters. Making consistent 3300s will have a marginal effect on win rate because there are so few situations where it matters -- he has to play below MBD and above Sanga, and you have to draw specifically a 3300 on the second turn (or YOLO it on the first turn, or risk MM Zera, etc.)
- You can get some cheap wins from WSR and Raigeki, but not many.

SETO 3
- See separate paste: https://pastebin.com/hjA5hT9U

DARKNITE
- Seems surprisingly straightforward (lots of value in beating each of the three tiers -- Cosmo Queen, B. Skull, MBD), but more testing is needed.
- You can get lots of cheap wins from WSR.
- Very bad decks always have a reasonable chance of winning, but this isn't relevant with the decks you typically take, even in a vanilla WR attempt.

NITEMARE
- Your deck has less of an effect here because you draw fewer cards than on any other duel, and Nitemare can kill you especially quickly with BEUD. Making a 3300 has more value than on Heishin, but making a 3800 has less value.