Hey :)
Was your shiny 31 / 31 / 31 / 9 / 31 / 31 Harvest Trevenant SV traded, or did you just get it via MMing?
If you got it via MMing and not by SV trading, I would offer these shiny PKMN (all of them combined, none were SV traded):
Shiny Trapinch (Flygon)
Jolly
28-29/31/31/x/31/31
Quick Attack, Fury Cutter
Nest Ball
d
Shiny Goomy
Modest
Gooey
24-25/28-29/31/31/31/0
Lv. 1 UT
Acid Armor, Counter, Iron Tail, Curse
Poke Ball
Shiny Riolu
Adamant
Inner Focus
Lv. 1 UT
31/31/x/x/31/31
Bullet Punch, Crunch, Blaze Kick