as far as i can tell its
1: Widowmaker - Overwatch (it's not sombra that's the camera to hint OW, clearly Widowmaker)
2: Zelda (and presumably link) - LoZ
3: 2b - NieR
4: Rem (and seemingly Roswaal :( ) - Re:Zero
5: Midnight and Mt. Lady (with Mineta and Deku in background) - MHA
6: just some fingers idk
7: idk this one but i heard its Shantae-Shantae
8: idk
9: Ichigo and Yourouichi-Bleach (Thought it was Benimaru and Shion from Slime Datta lol)
10: idk
11: Someone said kazuto and suguha-SAO and they might be right :/
12: Jessica Rabbit