Be able to choose your bots, so you can practice against a hero you struggle against.
Cool down modifiers, so you can either have super spammy abilities or abilities that you only get to use every 60 seconds.
Health and damage modifiers, so you can make a super beefy Montana or a Montana with double damage, damage modifiers should be separate for attacks and skills.
Time modifiers, so you don’t have a time limit or you can have a short brief time limit
Last but certainly not least, Starting level, so whenever you start the match you can choose what helix level you want everyone to start at. Which would allow people to practice with which helixes synergize well together, and it would be fun to start your heroes late game.