Ah yes. The issue of dropping and bye balance.
The first issue I had here was enforcing the "disruption points" system, especially with war coming up. The solution I'm considering is having the player who fails to make their fight drop to 0 points. If a player with 0 points fails to make a fight, they're out.
Hopefully this will eliminate players who never played clogging up the system, at least better than my lazy butt did.
The bye system was originally intended to only be given to a player with 0 points, when there's an odd number of players. When players dropped, and opponents had no one to play against, I decided in the beginning to count it as a bye, when I shouldn't have. That should have been a 0-0 win, like the rest.
Those rules fixes, in addition to the upgrading card system, are what I would add if I ran this again.
Other optional CotO variants:
You earn cards for winning, much like in war. You cannot lose more than your mono. You win by building your opposite's mono, a second mono in general, getting every card, or just getting a certain number of cards. Losing a match could cause players to have to "forget" cards, or cards could be cemented.
Another war-hybrid idea, you can only learn cards your opponent played, as though by beating them, you learned through experience one of their techniques. After having fireballs thrown at you, you learn to make one of your own.
Duel choice variants. Single elimination variants, round robin, a non-score based system in general, whatever.
Mini oracle trophy should be out later today.