Instead of the usual "create your own spells" this time we just create concepts we'd like to see in future spells. For example Kingsisle staff have recently created new spells which have uses never seen before where damage can be spread (although lowered) depending on how many enemies are on the field.
I'll start:
How about sacrificial spells, like immolate, they deal high damaging attacks at a lower pip cost but with the risk of damaging yourself. They wouldn't just have to be self-damaging as well, instead they could cause the user to be self-stunned or receive a -50% weakness or so on after use. Of course the damage would vary depending on the burden of the spell, being stunned for a round in pvp after using a spell could easily decide the winner while a weakness would instead be easy to get rid off.
I think it's an interesting way to bring in even more powerful spells that wizard101 has been trying to introduce but also not upset the already established pvp gameplay, you could even add self dispels onto the burdens when using the spells to make it more of a final gambit rather than constantly being spammed.
I'd love to hear other peoples ideas for new spells, feel free to add in an example of what the spell would look like too!