Help setting up Partner Trainer

[OshawottOtterBijumaru]

I've been trying to add a partner trainer in my game I'm making, but there's hardly any tutorials about that on YouTube and I tried that method above but still won't work, even on the sprite I've been trying to get it to work on "Steven" From the devon corporation, I'm not sure what to do so I'm kinda screwed for now, besides I Need a Partner trainer to Aide me in stopping Team Galactic's evil plans Lol

EDIT: I've gotten this error which doesn't help...

Exception: RuntimeError
Message: Script error within event 1, map 142 (Route 515):
Exception: NoMethodError
Message: Section018:27:in `trigger'undefined method `trigger' for nil:NilClass
***Full script:
Kernel.pbAddDependency2(@event_id,"Steven",99)

Interpreter:243:in `pbExecuteScript'
Game_CommonEvent:58:in `refresh'
Game_CommonEvent:15:in `initialize'
PField_DependentEvents:158:in `new'
PField_DependentEvents:158:in `createEvent'
PField_DependentEvents:505:in `addEvent'
PField_DependentEvents:26:in `pbAddDependency2'
(eval):1:in `pbExecuteScript'
Interpreter:1606:in `eval'
Interpreter:243:in `pbExecuteScript'

Interpreter:276:in `pbExecuteScript'
Interpreter:1606:in `command_355'
Interpreter:494:in `execute_command'
Interpreter:193:in `update'
Interpreter:106:in `loop'
Interpreter:198:in `update'
Scene_Map:103:in `update'
Scene_Map:101:in `loop'
Scene_Map:114:in `update'
Scene_Map:68:in `main

I Really don't get it