I never used Retaliate for the Sunday Dungeon. It's really unecessary. Take a Black mage character and equip him/her with Waterga and Comet (for Galkichimera). If you use a summoner, give her Valefor. For your front-line fighters, give them good weapons and Double Cut or a Break ability (heck, Pound also works). A RW with a non-elemental SB is also great.
Frankly, unless you go into that dungeon with a whole party of level 30 or lower characters, or with less than 5 characters, there is no reason to lose more than one medal per stage. Give eggs to the new character(s) to bring them to a respectable level (35+) in order for them to not be walking liabilities (not to mention the more HP and Defense they have, the less you are susceptible to lose medals for Damage Taken), take other characters which are already 50+ (but not 65), and level up all of them. Better level up everyone at a slightly lower pace than to have to S/L like crazy, repeat only the first stage and miss out the Growth eggs at the end of the dungeon (5 Growth eggs = 1 Greater Growth egg = 50000 exp = nearly a full level for level 40+ characters); since you can run the entire dungeon a little less than 10 times in 24h, and you win 3 Growth eggs per completion, it really would be a waste to not grab those; not to mention the Lesser Growth eggs which can drop, they are a nice little bonus).
