I quit a year ago after the 400€ fiendsmith core into 360€ foowalos playset + 150€ impulse playset buckbroke me.
I really liked Vanquish Soul for locals, even though it wasn't really great.
Played it a lot on master duel as well.
Love heroes too btw., but heard the new evil ones weren't that good.

I might pick up K9 core and whatever else I might need (foowalos and stuff for extra deck?), + new vs cards.

Can you guys advise me of what to do if I should even bother?
People at locals say its a fun meta. Is the "investment" worth it or are bans on the horizon for the deck? Is it too good? I don't wanna be the local asshole either.
Already did that once with yubel.

K9 is the only recent shit that appeals to me visually.
I think I should be able to buy everything I need for less than 300€~ given I already have the older VS cards.