Any tips on dair camping? I really suck at it :/
Space horizontally, not just vertically
Mix up the timing of you Dairs and jumps. People tend to Dair immediately after their jump then wait till they fall before they Dair again. in other words jump > Dair immediately > Wait > jump > Dair immediately etc. It gets really perdicable, good opponents will see this and jump up and Uair you after your Dair. I like to mess around with the timing so they don't punish me. I somtimes do Jump > Dair immediately > jump > Dair immediately. However, you will end up high in the air, too high to pressure their shield. This is just good as a mix up if they are punishing a perdictable pattern.
If they are spot dodging your Dairs I usually just tornado, although there are other options. instead of Dair just air dodge into the ground and wait for their spot dodge to be over and punish.
If they try to outprioritize you with an Utilt or Usmash be very careful of your spacing. I like to just air dodge though their attack into the ground and punish with a SH Nair (lots of damage), although you can punish with pretty much anything. Also, I'm just theorizing (i.e. never tried this), but you could probably dimensional cape attack in this situation. It does 14% which is more than most of MK's attacks. This might piss your opponent off too, would is always great in a tournament match
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Edit: For some characters, Dair camping doesn't work well, that might be your problem.