One of my pet peeves are cards that create massive SP differences between players.
Dio, Mystere, & Sky Staff are the best return units because they can create massive SP differences between players on top of field advantage and they've been given the most incredibly extreme easy mode combo support which I feel were the worst thought out ideas ever to grace Alteil.
Expert Sorcerer & Mermaid Aquamancer have never been used as far as I can tell because they suck as units, their return skills cost more SP, and the designers seem to not give a damn about these common cards, so they neglect giving them any support like the rares got.
I think return units should be designed so
1. Their return skills never create more than 1 SP difference between players.
2. They do something useful on the field when the player doesn't have SP to return or just because it's stupid to have a useless unit sitting on the field when your facing down a bunch of deadly units.
I'm hesitant to suggest how cards should work, but here are some observations:
The people who made Aquamancer have no clue wtf they are doing in regards to game design. As long as Aquamancer has the possibility of returning friendly units, no one will ever touch her.
"But she won't return your friendly units if you don't play L4," you say.
Well, since when do L3 rushes have the incentive to put out a unit with stats like hers and then have 3 loose SP to use for skills? Same thing for Expert Sorcerer.
What if these units had good stats and maybe some skills that either benefit their tribe or can be used in some kind of Mid/Big blue build which will actually have some SP to spend? It's important that the units are not functionally useless so that the return skill on the unit isn't the sole reason for playing them; it would just be something extra the units could do given a good opportunity.
Then you won't have OP return that returns anything and everything every single turn, but a solid unit that provides support for a file and occasionaly can return some units to turn the tides of a battle.
Maybe... maybe... more rare cards like Dio or Mystere could be allowed to have their skills create a 2 SP difference between players. For example, if Dio returns:
L1: Dio player is on the losing end
L2: Both players even on SP
L3: Dio player 1 SP ahead
L4: Dio player is now 2 SP ahead, ouch!
L5: Dio player is now 3 SP ahead, so add condtion that opponent gets +1 SP.
L6: And so on...
The purpose of return should be about field control. It's shouldn't be about getting both field control and the equivalent of making the opponent eat up to 9 shades in one turn.
Buff return units, nerf their SP drain capability.
Personally, I think it could be fun if Expert Sorcerer's & Aquamancer's return skills worked like Withdraw Strategy, but with L3 and lower random target or a Cyclone-like skill.
Finally, don't waste any more time in undoing the ultimate cheese combos you created that prevent a player's units from acting and make them immediately get returned as soon as they're played. Shame on you as card designers for dumbing down control files so bad that you can face-roll the mouse to victory.
Abuser Punisher / Callonia