"... make portals! Definitely portals." you send her a feeling of amusement before giving her the ability to create 2 linked free-floating portals, and warning her that the edge can cut through anything. She can't put them inside solid objects, but the ability to slice things with the portals is still pretty dangerous.
Then you show her the options she can pick from the armory. She doesn't have a very big power budget, but she still has enough to pick up some boots that let her run extremely fast, jump really far, and perhaps the reason why she picked them, not get hurt when falling if she lands on them. She spends what's left on a re-usable grenade that coats anyone it hits with cellophane. It takes a good 10 minutes to recharge, and if she misses anyone they can probably get their team out pretty quickly, but given her power she has an easy way to deliver it, so all in all, not a bad choice.
You then deliver everyone to random points throughout the island with their teams. Since you have the final say in who goes where, you put Jessie with Martin and Cass, because of course you will! Upon arriving, Jessie quickly looks around, and finding herself in a cave, looks outside. Seeing no one nearby, she goes back. "There's no one nearby" Says Cass, "My power's telling me we have a while even if someone comes straight towards us. We got lucky, no one's nearby at all." Looking at her, she didn't take much in the way of equipment. The only piece she grabbed is a big giant barreled gun, well cannon more like it, with a dial on the size. It looks incredibly cartoony. Martin meanwhile, doesn't seem to have much either. He has a pouch and his suit looks kind of different, shimmery almost. "First things first," Jessie starts, already taking charge like she normally does, "what are your powers?" "Mine allow me to pretty much see everything which is happening, and to know what powers someone has," Cass replies, "It's a little more complicated than that, but that's the gist of it." "Mine allows me to change someone into non-living material" says Martin. "I have to touch them or their clothes though, apparently the suits count as part of your skin because they're so thin. Anyway, if I can get to someone, I can turn them into a statue or hammer or some other simple object." "I can create portals" Jessie says, "Not much else to it except I need to be able to see my target. What equipment did you get though? I got these boots which let me jump and move better and a cellophane grenade, I didn't have much to spend." Cass pulls her giant gun off of her back and smiles, "I might have gotten a useless power, but I got to buy half the store and load it into this thing. This'll shoot any of the projectiles that were in the store." "Like what?" Jessie asks. "Like this!" Cass says as she twists the dial and shoots it at Martin. His eyes go wide as a small red and white object launches at him. It taps him on the head and he dissolves into light. The object twitches for a moment before falling apart, causing the light to emerge which re-solidifies into Martin. "What was that for!" he asks. "An example" Cass says. Jessie's only comment out loud is to say, "Cool." Mentally though, she complains to you, "Really, a pokeball?" To which you simply send her a feeling of amusement. Martin grumbles for a second, then vanishes. Cass jumps back in surprise, but Jessie simply says, "Cool, invisibility, that why your suit looks weird?" He reappears as suddenly as he vanished, "Yea. I figured the only way I was going to be able to use my power was by doing this. I also picked up a couple fun things," he says pulling things out of his pouch. "This thing here can apparently let me freeze someone's muscles for 3 seconds from a distance, but it takes 3 minutes to charge." He holds up a small little pronged device with a button. Then he pulls out a collar-like device, "This stops people from using their powers, but it has to be around their neck. Apparently they can't take it off, and it also comes with this remote control which is supposed to show options once you put it on someone." He reaches in and pulls out three little triangles, "This is the last thing I got, we put these on our foreheads and it should let us communicate mentally." He puts one of the three onto his head and it melts into his skin. Jessie grabs one and does the same. Cass though, pushes his hand away. "Come on Cass," Jessie said, "If we're going to win this, we need every advantage we can get." Yea, but.. Do you need to get in my head? "It's not so much in your head as you can choose to talk to the other person silently and more quickly," Martin says, "Think of a walkie-talkie, you need to press the button for the other person to hear you." "Alright..." She says apprehensively and slaps one on her head.
"Alright, next thing" your sister says, "do we want to stay here and let the others fight amongst each other for a while, or should we move on? "Staying here sounds good to me." Says Martin. Cass seconds the decision, and they start settling down. You push the idea that you're going to spring a trap soon if they stay there to Jessie, and she mentally responds, "I know, make it good!"
Thinking, you decide to let them find something deeper in the cave.