Satsuka being abused as a defense... is so hilariously fitting, I'm speechless.
(She's sort of masochistic, so yeah...) The same goes for Nuke
TheCat being an attacker, hehe.
Couldn't find any way to reliably trick the CPU into losing all the time, which is good, I guess. As you stated in the help file, the battle part is indeed pretty similar to rock-paper-scizzors.
I've got a few questions about the warfield part, though. First of all, does Satsuka have any purpose other than stalling the opponent? Setting up a Satsuka requires one turn, setting up and attacking with a NukeTheCat requires two turns and destroys one Satsuka. However, I could just as well ignore the presence of Satsuka and set up a Nuke or attack with one whenever I get a turn, since I can simply get Hiznopellagio and Lawsome back online if they do get hit, which also only costs a single turn and they pretty much serve the same purpose as Satsuka (other than the fact that I can't attack when they're not online). As of right now, it seems like Satsuka is only a way of making the battles last way longer, but she has no purpose other than that.
A similar question about Nuke - does it make any sense to set up more than one? You can only attack with one of your Nukes when you choose to attack during a turn, after all, so setting up more than one Nuke seems pointless.
Here's an idea to work around the things above: Having multiple Nukes set up allows you to attack with all of them at once. So instead of setting up a Nuke, attacking, setting up a Nuke, attacking, which would require a total of 4 turns, you could set up a Nuke, set up another Nuke and THEN attack, resulting in both Nukes attacking with only three turns spent. To prevent this from becoming too abuse-able, you could add the ability to attack the Nukes of your opponents as well, but ONLY if your opponent has no Satsukas. Also, whenever you attack the opponent's Nukes, you will kill ALL of them, but it only costs you a single Nuke. So if you have two Nukes and your opponent has three (both have no Satsukas) and you choose to attack, your first Nuke would kill the three Nukes of your opponent, and your second Nuke would attack their Hiznopellagio/Lawsome/the PEACE letters. Speaking of the PEACE letters, I'm having a feeling that with the above setup (if you do decide to make the game work that way), it would probably be better if there was no way to recover them. So once a letter is lost, it is lost until either side wins.
I do realize that this would be a heavy modification of how the game this is based off of works, but that way, I think there would be a bit more strategy involved instead of pure luck-based rock-paper-scizzors, and it would also make the currently useless/pointless/whatever things actually useful. Let me know what you think.
Also, since you asked us to comment on how well you remade our avatars/characters/whatever: You forgot Satsuka's gloves. (...actually, looking at Satsuka's sprite in the Ikayuna demo, I also forgot them there, and you likely based the drawing in this game off of that. Oops. I knew it would've been a good idea to give you her concept art...) The rest was accurate, and in your usual simplistic style.