Are those Swarms comparable to her in strength? If they're weak as in
Wall level and such then it isn't worth that much since they're something that can be defeated easily
Does Celistia have to use her energy if she wants to use her Flight/Teleportation/Forcefield? If she does then she'll probably won't be able to use them after overusage, depleting her energy
Can her Forcefield be broken and how many spam attacks can it withstand before breaking? Said spam attacks are likely comparable to her basic bear shaped fire attack (because making her attacks have a bear shape make them even more powerful). At the very least she can spam her attacks with bear shapes to make them stronger so they'll break the Forcefield if it can't withstand that much
Are Lisesharte's Legion's Homing Attacks comparable to
City Block level? It's easier defeating a horde of enemies who is hilariously weaker than you, as in if they aren't
City Block level in this case while being
Wall level then they aren't worth that much.
Celistia won't be able to see what's beyond the wall so Yuna could bait her and such, such as when she baited the giant snake to open its fangs at her when she jumped so she could put the fire bears inside it. Could also make the decoy (although there's no context on how it fully functions cause the Series is based on a Novel so the explanations are probably in the Novel) She could also make it bigger at the sides such as when she made pretty high when the wolves were attacking her too
Kumayuru and Kumakyuu can exert their Aura, which is useful against fodders I guess.
Kumayuru and Kumakyuu can also lift Celistia Ralgris and probably grab her arms so she won't be able to use them -
https://i.imgur.com/bnly9XJ.png
Kumayuru and Kumakyuu can be used as transportation so they'll just run around while Yuna spams her attacks
Based on the picture it looks like it's a "clone" (as there weren't enough context around it), certainly not an illusion. The black snake hit the decoy which turned into pieces of rocks that spelled out "decoy"
Defeating someone who can freeze someone Ôëá resisting their freeze unless if you actually got hit by them
There wasn't any picture shown for how she trapped the enemy inside the water but it probably functions like this -
https://i.imgur.com/DTvnlol.png
Yuna can leap pretty damn high so if Celistia wants to play the air game then she'll just leap at her over and over again or make a tactic on how to beat her. She could just try riding Kumayuru or Kumakyuu and running away from Celistia so she'd have to chase her, exhausting her (if her Flight requires energy)
But yeah, that paralyze for dozens of seconds would give Celistia enough time to barrage Yuna so she does win more often than not. That Flight/Teleportation countered Yuna pretty bad for the giant hole and homing attacks