Invoker is the most versatile hero. What things are needed for the Invoker?
The Invoker knows nothing about a specific command, only the command interface is known.
The Invoker does not know anything about a concrete command,
it knows only about command interface.
A return statement with an Expression attempts to transfer control to the Invoker of the method that contains it;
Invoker is itselfversatile, absolutely universal
and incredibly complex character in DOTA 2, which is why it is not very widespread.
There can be some weird cases, for example Faize,
whose auto attacks are melee but is an Invoker who casts skills from range.
However, due to the very strong complexity of managing this character,
very few people know about what things to buy on Invoker and how to manage them at all.