Okay well forger is extremely under powered and is a lot weaker than janitor.
Maybe the forger should have additional abilities.
Ability Buff:
Rewrite the target's role
Rewrite the last will of their targets
Rewrite the death note of their targets
Rewrite the reason their target dies
View the original role
View the original last will
View the original death note
View the original reason their target dies
Basically, the forger can actually rewrite someone's death entirely.