I just ordered the O2 + SDAC from Drop and noticed I will have to order an extra power adapter for EU. This puts me over the price of a Fiio K5 Pro. Should I get the Fiio instead? I see the Fiio can deliver more power but does it sound better?

From the reviews i read, the bass and treble on the dt990 can be quite overwhelming to the point where its unenjoyable. Personally i do like some V shape sound signature but if it makes it unenjoyable, then thats just not worth it in my opinion. But from reviews ive read, the 600 ohm version...

I would say the budget is around €250-€300 can go over a little

Those seem to not be available anymore in my country and otherwise just as expensive, if not more expensive as the hd6xx. Which one should I get then?

I'm very new to all of this but have been doing a lot of reading on new headphones but can't decide what to buy. I don't have a DAC or amp. I will mostly use these headphones for gaming (often times competitive shooters like csgo) while on the call with friends and some light music listening or...