Collect Call / Broadcast

You've abused the Sending Spell to the point where you've learned to adapt it in two higher forms:
Collect Call Sending:
Rather then sending a short message you can attempt to contact a target you are familiar with and request a Collect Call.  This can be a message up to 25 words but must end with 'Do you accept the charge?'. If Yes they must expand a resource (eg. 1 Sorcery Point, Ki Point, or Level 1 spell slot) and their concentration to open their mind to accept your sending.
If they refuse the spell fails and you must pay the charge yourself.

If accepted you may communicate with them via the sending spell freely for up to 10 minutes as long as both targets maintain concentration.

Broadcast Sending:
You can attempt to send the same 25 word message to multiple people prescribed by a general description or list of names - eg 'city guard of waterdeep', 'my party', 'powerful wizards open to a long distance relationship with a beautiful Elven Litch.. no evildoers please'.
Roll a D10. You contact up to that many minds. Alternatively roll a D20 You attempt to contact up to this many but take psychic damage equal to the number of additional minds over 10 that you reach from overextending your mind. The DM will advise how many minds you contact, damage (if any) and any responses you receive to your sending. 

Upcast: each slot above 4th doubles both the range of broadcast and the extended range/damage. eg 1D20/2D20 for 5th, 2D20/4D20 for 6th, 4D20/8D20 for 7th and 8D20/16D20 for 8th and up to a 10D100/Unlimited for 9th.