OK, so:

- If Paramount ever decides to adapt Sonic 2006, they'll undoubtedly cut out Princess Elise. Yeah, she deserves better than that, but she's a controversial enough character among the fandom that they'll probably just do without entirely.
- One of the reasons for this controversy is the fact that she kisses Sonic to revive him after he gets killed by the game's central antagonist, Mephiles the Dark.
- Sonic "dying" is an iconic enough moment that it'd be basically mandatory.
- In Sonic 2006, Princess Elise is the unwilling host of the Flames of Disaster, which have apocalyptic implications and contain part of the entity which serves as the final boss.
- In the Paramount continuity, Knuckles has "the Flames of Disaster" as an ability which he can just do.

Therefore, if Paramount does a Sonic 2006 adaptation, Knuckles will take on Elise's role of being the unwilling host, which means that
he will be the one to kiss Sonic,