I use sakura, since it has great support for unicode (presumably through libvte, which also xfce4-terminal uses). See e.g. https://i.imgur.com/G6arkK9.png using some extracts from http://www.madore.org/~david/misc/unitest/

- xterm just gives up (tried uxterm as well as the .Xresources settings here)

- st prints the arabic backwards (left to right, which I suppose you might prefer if you don't actually plan on reading it), has no colour on the emoji (which again you might prefer!), and completely fails to display the double-composed diacritics (this is a bad one, even if you prefer to KISS)

- I don't know what kitty is doing with the arabic, all I see are some strange rendering artifacts

- sakura (and xfce4-terminal) passes all the tests