maybe at some point, you could add something like difficulty's to arena mode?
like, normal mode would be the base game, how it is right now
but a hard mode could spawn more enemy's, give you less stuff, and maybe even spawn you without a weapon, and waves come a lot faster. plus enemies would have more health.
then easy mode would just be, stuff like, more health, more mana, less enemy's, maybe even something like the player getting 2 turns instead of 1
also, little recommendation, i feel like it would be smart if every enemy turn, not every enemy did an action all at once, cause at some point, it just becomes impossible to win when the enemy has more health then you, and is way too close to attack without risking yourself, so it'd be cool if every enemy only had the chance to do an action every turn
and jumping on an idea by looksalittle, of there being some kind of sandbox mode where you can do stuff like spawn in items, enemies, even have stuff like infinite points for skills, togglable inf mana, togglable inf health, and respawning if you do die