@DerVVulfman
The root cause was finally discovered.
Gandalf was not hiding in the Runic Script, no.
Well, technically, he was.
This is how it all happened.

1: Gandalf entered MICROSOFT EDGE. 
2: Gandalf SLIPPED IN UNNOTICED when I copied your Runic Script. 
3: Gandalf got out and did his well known "You shall not pass!" via "For..." line errors. 

Luckily, Mozilla Firefox saved the day which made sure Gandalf is permanently gone though he still resides in Microsoft Edge so for those who are using Microsoft Edge, be warned.
My personal lesson learned: Do NOT use Microsoft Edge for these script copying purposes from now on, ever. 

Must be the same cause which made me gave up on VX Ace which has much more features and an existing Runic-like script.
Now that I know, never shall I, again (for the 3rd time), use Microsoft Edge for RPG Maker purposes. 

No surprise if edge were not configured to use UTF-8 encoding, perhaps its current encoding might be some ISO-8998 something, Ruby and RGSS use UTF-8 by default.