A huge (and two days late) collaboration between dsp2003, Tails_Doll and AnonymousHatter.
 
Features: Apple Leaves, Auntie Orange, Bubblegum Blossom, Button’s Mom, Cloudy Quartz, Cookie Crumbles (Rarity’s Mom), Cup Cake, Derpy Hooves, Floribunda, (Gr)Annie Smith, Milky Way, Millie, Mrs. Paleo, Mrs. Shy (Fluttershy’s Mom), Princess Cadance, Queen Chrysalis, Sew-and-so, Spoiled Rich, Stormy Flare (Spitfire’s Mom), Trixie’s Mom, Twilight Velvet (Twilight’s Mom), Windy Whistles (Rainbow Dash’s Mom)  

 
Some notes from me:
 
Due to technical troubles and other circumstances, I had to once again maintain most of the drawing. Welp.
 
Participation in percentages:
 
dsp2003:  
BG - 70%, 10 ponies, various fixes
 
Tails_Doll:  
BG - 30%, 6 ponies, initial idea, bg sketching
 
AnonHatter:  
BG - 0%, 6 ponies
 
Originally the characters were also supposed to be shaded, but the amount of time put into this drawing was already bordering on the edge of sanity, not to mention I also had to split this drawing across three different PSD files due to SAI’s 255 layer limit being hit multiple times.
 
Edit: I’ve noticed a couple of bugs that ended up in the finalized picture (missing shadow of one of the pillars, missing cutie mark of Cadance and missing green on Chrysalis’ belly), so they are now corrected.