You should not try to pull. Pulling is intended only for vanilla TC.
I recommend trying applying the modifications as .diff
root@ns3033723 MINGW64 ~/Desktop/sc/Sunwell (master)
$ git apply transmog.diff
error: patch failed: src/server/game/DataStores/DBCStores.cpp:122
error: src/server/game/DataStores/DBCStores.cpp: patch does not apply
error: patch failed: src/server/game/DataStores/DBCStores.h:134
error: src/server/game/DataStores/DBCStores.h: patch does not apply
error: patch failed: src/server/game/DataStores/DBCStructure.h:1171
error: src/server/game/DataStores/DBCStructure.h: patch does not apply
error: patch failed: src/server/game/DataStores/DBCfmt.h:75
error: src/server/game/DataStores/DBCfmt.h: patch does not apply
error: patch failed: src/server/game/Entities/Player/Player.cpp:12078
error: src/server/game/Entities/Player/Player.cpp: patch does not apply
error: patch failed: src/server/game/Entities/Player/Player.h:29
error: src/server/game/Entities/Player/Player.h: patch does not apply
error: patch failed: src/server/game/Handlers/SpellHandler.cpp:26
error: src/server/game/Handlers/SpellHandler.cpp: patch does not apply
error: src/server/scripts/Custom/custom_script_loader.cpp: No such file or directory
error: patch failed: src/server/scripts/Spells/spell_generic.cpp:38
error: src/server/scripts/Spells/spell_generic.cpp: patch does not apply
error: patch failed: src/server/worldserver/worldserver.conf.dist:3719
error: src/server/worldserver/worldserver.conf.dist: patch does not apply