1 Turtle Dragon 1 < Maple 12 (Banshee was busy)
2 Love Dragon 1 < Banshee 12
3 Peacock Dragon 1 < Banshee 12
4 Sterling Silver Dragon 2 < Banshee 12
5 Hypnotic Dragon 2 < Banshee 12
6 Turquoise Dragon 3 < Banshee 12
7 Mask Dragon 3 < Banshee 12
8 Leviathan Dragon 5 < Banshee 12
9 Rose Dragon 6 < Banshee 12
10 Medusa Dragon 6 < Banshee 12
11 Brazil Dragon 6 < Banshee 12
12 Marble Dragon 8 < Banshee 12
13 Psychedelic Dragon 8 < Banshee 12
14 Hibiscus Dragon 9 < Banshee 12
15 Nouveau Dragon 12 < Banshee 12
16 Trickster Dragon 9 < Banshee 12
17 Deep Dragon 9 < Maple 12 (lost Banshee 12)
18 Coral Dragon 9 < Banshee 12
19 Eclipse 12 < Banshee 12
20 Rogue 14 < Darksteel 10 (lost Banshee 12 twice, Maple 12, some champions...)
21 Serpent 12 < Maple 12
22 Sweet Tooth 14 < Banshee 12
23 Cupcake 16 < Banshee 12
24 Poison Ivy 17 < Banshee 12
25 Kung-fu 19 < Banshee 12
26 Sugar Plum 18 < Maple 12 (lost Banshee)
27 Iris 18 < Banshee 12
28 Cauldron 20 < Ghost Armor 10 just one M (lost Banshee 12 , Maple 12, ...)
29 Unicorn 20 < Comic 10 (lost Ghost Armor)
30 Venomous Dragon 20 < Banshee 13 (not a typo, I leveled him up for last battle)
As you can see, I'm banking on the "use the newest dragon from other competition" theory. So far so great! Although I didn't document the method used, I generally start with a Magic and if that nearly knocks them out then I'll go with a second Magic. Otherwise I'll follow up with two Bashes.