Here is the full list of all 32 UBERMOSH:SANTICIDE achievements. It takes around 0-1 hour to unlock all of the achievements on Windows.
SURVIVE SANTICIDE, SCORE 1000, NO CLASS MODS
SCORE 1300, GUNNER CLASS MOD
SURVIVE SANTICIDE, SCORE 1000, GUNNER CLASS MOD
SURVIVE SANTICIDE, SCORE 1000, SINGLE DOUBLE TRIPLE
SCORE 1300, NO CLASS MODS
SURVIVE AN EVENT, WRAITH CLASS MOD
SCORE 1000, WRAITH CLASS MOD
SCORE 1300, WRAITH CLASS MOD
SURVIVE SANTICIDE, SCORE 1000, WRAITH CLASS MOD
SCORE 1300, PSYKER CLASS MOD
SCORE 1600
SURVIVE AN EVENT, PSYKER CLASS MOD
SCORE 1000, PSYKER CLASS MOD
SURVIVE SANTICIDE, SCORE 1000, PSYKER CLASS MOD
SURVIVE AN EVENT, CATALYST CLASS MOD
SCORE 1000, CATALYST CLASS MOD
SCORE 1300, CATALYST CLASS MOD
SURVIVE SANTICIDE, SCORE 1000, CATALYST CLASS MOD
SURVIVE AN EVENT, WARLOCK CLASS MOD
SCORE 1300, WARLOCK CLASS MOD
SURVIVE SANTICIDE, SCORE 1000, WARLOCK CLASS MOD
SURVIVE SANTICIDE, SCORE 1000, SINGLE STRIKE+SHREDDER
SCORE 1000, WARLOCK CLASS MOD
SURVIVE AN EVENT, GUNNER CLASS MOD
SCORE 1000, GUNNER CLASS MOD
SURVIVE AN EVENT, KENSAI CLASS MOD
SURVIVE SANTICIDE, SCORE 1000, KENSAI CLASS MOD
SURVIVE SANTICIDE, SCORE 1000, DOUBLE STRIKE
SCORE 1000, KENSAI CLASS MOD
SCORE 1300, KENSAI CLASS MOD
SURVIVE AN EVENT, NO CLASS MODS
SCORE 1000, NO CLASS MODS