I use 3. I never use anything integrated into an IDE for some reason, never started and probably never will.
Yakuake as drop down terminal 90%
Black box for nice looking full screen terminal for full screen.
Dolphin with emulator on bottom for niche things
If I could only have one for the rest of my life I’d be torn between Yakuake and Konsole. I love Konsole though, used it for years and is all round great for sticking with the DE aesthetics and integrating with themes.