If that Esdeath calc places her at Small Town level (which is a massive lowball tbh), and Tatsumi actually matched her in combat, Tatsumi in his evolved from should at least scale to Esdeath, if not higher,meaning he gets upgraded to Low 7-C. Keep in mind that Esdeath's lake freezing calc was calculated based on what was just shown on the panel only. Esdeath may have frozen the entire lake instead.
However, if Esdeath actually froze the entire lake instead of just freezing what was shown, we actually get a value bordering on
Small City level. I will calculate this if necessary.
Now, there are a couple characters that can scale to this. Based on these calculations, the characters that would apply to these upgrades based on the calculations posted:
Esdeath freezing a lake
Budou splits a cloud
Lightning Dodging
City Level: Tatsumi (2nd form Incursio), Esdeath, Budou, Mine (Pumpkin's last attack)
MHS Speed: Tatsumi (2nd form Incursio), Esdeath (can casually match 2nd form Incursio), Budou
Hypersonic+ with MHS reactions: All other AgK characters.
Now about the AP of those other characters.....Akame, in particular, should be given consideration for matching Esdeath in combat.