I could say something for Edward, but he already has some lol. So I’ll start with the others–
Desmond: he’d have the Assassin symbol somewhere on the inside of his arm, or on the back of his shoulder. I don’t think he’d do matching ones with his SO unless she can keep the organization a secret, and make sure not to betray him like Lucy did…
Aveline: I think she would have some geometric, First Civilization designs on her arms.
Shay: He’d get one on the back of his neck that only you could see if he ties his hair up. And it would be the Templar Cross tattoo.
– Ezio
I won’t include characters that already have tattoos obviously 😀 I’m also linking the designs to give you a better idea on how they’d look like.
Altaïr: A wing on his back that extends to his arm. I don’t really see it as an eagle motif, more like a “fallen angel” kind of theme. His SO can get a matching one on their other arm 😀
Ezio: A geometric tattoo that extends from forearm to his hand. Or something simple like this on his forearm.
Connor: Setting aside the natural choices like tattoos that respect his culture, for some reason I see him (his modern self especially) getting a pretty badass looking 3D tattoo like this.
Aveline: This one on her back.
Adéwalé: A simple design that runs the length of his spine like this
Haytham: I don’t really see him as someone who would get a tattoo, but for the sake of this question I can see him as someone who would get something subtle such as the Crux constellation on his hip, something that he could hide with his underwear XD
Shay: His favourite quotes tattooed around his wrists.
Arno: A text that goes “Insert coin in slot” just above his butt This design on his lower back (HEY I have you guys to thank for discovering the religion that is Arno’s Butt Appreciation™) I can see his SO getting the same on their belly XD
Shao Jun: Something like this around her wrist. Her SO would get the same one on their wrists, too.
Arbaaz: Geometric mandala designs on his legs and maybe even his arms.
Evie: Something sneaky, like a pretty but small flower tattoo on her lower back, maybe something like this.
~ Signora Paola
Same, I will only mention those who, to my knowledge, don’t have tattoos
Altaïr: Tribal designs on his upper or lower arms, both arms.
Ezio: Flowers or something romantic on his lower torso, you would have to take his pants off to see it… ( ͡° ͜ʖ ͡°)
Connor: Anchor or native totems (wolf, eagle or bear) on his big, muscular back.
Aveline: Birds or flowers on the back of her neck, only a few selected get to see it.
Adéwalé: Some skulls or crosses on his chest, but also ropes or anchors since he;s a sailor as well.
Haytham: A subtle templar cross on his chest, over his heart.
Shay: Tribal design on his back or maybe some sailor design on his torso.
Arno: Most likely a watercolor tattoo of the French flag on his back and maybe Elise’s name tattooed on his chest.
Shao Jun: A dragon tattoo that starts with the head at her shoulder and runs all the way to her thigh.
Arbaaz: I like thinking he has a cobra tattoo in his back.
Evie: Would probably have the Assassin crest in her wrist, or maybe another symbol on the back of her ears.
~Claudia