This was an Earth versus Water battle with mostly magic monsters.
The rule set here allows for 21 mana which is a little on the small side, has Knockout for All which isn't really useful unless one of the monsters has the Stun ability which will then result in double damage to stunned monsters, Divine Shield for All which will ignore all first attacks to all monsters, and no Dragon Splinter summoners or monsters are allowed.
For this type of rule set I went with a magic team due to the small amount of mana that we were allowed, which is why I called this battle my "Mighty Mini Magic Tea," since they're all mosnters with small amounts of mana.
My summoner was Obsidian due to her giving a magic boost to Earth magic monsters.
In 1st position I had Failed Summoner due to his Magic Reflect ability which would return a reduced amount back at magic opponents but also he does a good job as a mini attack sponge, meaning he doesn't last very long.
2nd position was Spirit Shaman due to his small mana cost. He already has Divine Shield but unfortunately Divine Shield doesn't stack.
In 3rd position I had Goblin Sorcerer who I picked again because of the small mana cost and there speed of 2 whic isnt' bad.
In 4th position, I picked Creeping Ooze due to its Slow ability which would lower enemy speed and give my guys a little more of a chance.
In 5th position I had Mycelic Queen who gave everyone extra armor due to her Protect ability.
In last and sixth place I had Djinn Biljka who has Camouflage and Void, which meant that no one could attack Biljka until it was in 1st position and that it would receive reduced magic damage.
All of these monsters magic ability would be increased by Obsidian.
The enemy team had Ruler of the Seas and Wavesmith which worried me a little since Ruler has the Blast ability and Wavesmith has decent attack power, thankfully Divine Shield ended up protecting me enough here.