Some useful combos in this deck:

Pathfinder + Flame of the First Ones
Since we're being forced to move every turn, might as well deal damage while we do it
Pathfinder + Release the Hounds
Normally the usefulness of this card is reduced by the requirement for the hounds to be summoned at the Avatar's site, but we're a very mobile avatar so there is a good chance for clutch movement
Any of the lethal minions + Blaze of Glory
Even a 1 power Pufferfish can take out an entire site if it's immortal until it finishes attacking everything
Cloud Spirit + Maddening Bells
Movement + 2 means they can get across the board on a turn to ensure they're minimizing effectiveness of every spellcaster on the opponent's side
Deep-Sea Mermaids + Rivers
If we keep being forced to put cards on the bottom of our deck we might as well draw from it on occasion
Deep-Sea Mermaids + Fire Harpoons!
Submerge, cast, drown, repeat.
Broomstick Witch + Bone Spear + Raise Militia
Move witches to border sites, cast Raise Militia, you have all the fuel you need to shoot spears all over the board

Wanderlust