The flier is definitely hostile and that didn't look like Tinkertech up close—maybe they're just nonEvil straight up and attacking her anyway. Maybe she has a chance to get this whole thing to calm down somehow. She could Holy Smite, which would be useful information but also hostile. She yells at the gunman sticking his head out, "What are you trying to accomplish?" and starts emitting an aura of holy peace that makes everyone need to think for a moment before trying to hurt her.

The guy in the van looks tremendously frustrated, and maybe a little relieved?  He doesn't answer your question, but he also doesn't throw a grenade at you, or blast you with lightning, or whatever else he was thinking of.  The van itself falls back a little more, and drifts right until it's exactly straddling the two lanes.

The flier is still accelerating, but apparently they're still more than thirty feet away because they take three more shots at you.  The first one ricochets off your rear tire (no part of the bike is Tinkertech, but Armsmaster did make a few product recommendations).  The second lodges in the rear door of the semi trailer -- it's about as big across as your hand, circular-ish, and burning so hot it's almost white.  The third misses your one remaining mirror by about half an inch.

Thank you Armsmaster for having good taste in bikes. The traffic behind them has fallen back enough that Samora can take up two lanes, slaloming back and forth to dodge enemy fire and also get a good view of the road ahead, looking for an exit or enough shoulder to get on the far side of the semi. While she still has a mirror, what's the car the cape launched from up to?

And she'll cast another Cure Moderate while she's at it; it's a good one and she's almost completely fine again (21 HP of healing). 

The van keeps station, ready to smear you into the semi or the barrier if you try to pass.  The door is still open but nobody's peeking out of anymore.  Ahead of it, the truck is maintaining speed exactly.  The flier, meanwhile, is still getting faster: they're almost directly above you now.  They haven't taken any more shots.  The car they came from is slowly working its way through the deccelerating traffic behind you; drivers are starting to get out of its way.

After a few rounds of this, you spot a sign overhead: "NEXT EXIT 2 MILES".

That's going to run out the clock on her Sanctuary aura. They picked a good spot to be completely irresponsible in. She toggles the aura off to test whether that immediately draws fire or if anyone is authentically rethinking their life choices, and keeps making evasive maneuvers. And contemplates calling the PRT for backup, but even if she could get her tablet out of her bag while dodging it would be hard to make herself heard over the road noise. Something to do later. 

The van's back door rattles, then opens, and one of the gunmen drops something the size of a marble on the road surface.  It skips once, then abruptly grows into a steel ball nine feet wide, rolling down the lane divider.

That forces her fully into the right lane behind the semi, and she gives it a wide berth in case it's going to explode or something, but it just rolls off behind her toward the no-doubt horrendous traffic jam in the battle's wake. It occurs to her that someone might have already called the PRT, what with all the gunfire and the very obvious flying cape shooting at the road. Can't count on it, though. 

The thrower watches you dodge with clear and profound mixed feelings. Behind you the marble bounces twice, and the traffic jam starts to panic, but then suddenly it goes from rolling-boulder-trap-sized to marble-sized again. Visibly relieved, the thrower tosses a second abruptly-giant marble onto the left lane, and then a third, trapping you on the right. Then the van stats to decelerate.

Above, the flier has fully matched your speed, and is a steady fifteen feet behind and fifteen feet up, slowly dropping. They haven't fired off any more of their dozens of orbiting projectiles.  There's maybe a faint suggestion of a feminine shape through the bright yellow flame.

She keeps dodging. Time is on her side, here: every moment nothing happens is a moment for these people to reconsider why they're doing this, and a hundred yards closer to the next exit. 

Your mystery attackers seem to think it's the other way around!  The thrower gradually gets bolder, but he's content to clutter up the left lane and leave you stuck in the right.  Then, finally, the rear car breaks clear of the traffic jam and roars up behind you, while the van continues to decelerate ahead of you.

The plan seems to be to crush you between them, but you've got a few seconds before they converge.  Now what?

So that's what they were up to.

She swings out to the right, gets between the van and the semi, and before the van can pivot to crushing her against the trailer she rams them, flinging herself off the motorcycle and into the open door of the van. (Goodbye motorcycle, you served faithfully and well.)

It's not the most elegant of maneuvers. Quite inelegant, really, and she ends up dragging her legs on the pavement for a second or two (13 damage). But what she lacks in grace she makes up for in magically enhanced strength.

Now there's an angry cleric drawing a sword in your van, that's what.

The two remaining shooters lurch backward against their harnesses, but the thrower looks excited!  By the time you pull yourself up into the van, he's a foot taller and still growing.  He tries and fails to stop you drawing your sword, but he does manage to grab a big fistful of cloak.  The plan seems to be to throw you right back out again.

Can't throw her out of the van when her legs are clamped around his leg and her elbow is clamped on his arm and her shield is getting in his face!

A better wrestler probably could; he's a lot stronger than you are, and still getting bigger.  But he can't seem to apply his strength in enough different places at once, and his friends behind him haven't yet figured out how to shoot you without either getting unstrapped or maybe also shooting him.  They sure are intensely focused on the problem, though!

So things are going great, except a sudden flare of heat and light indicates that the flier is now right behind you.  There's a sound like tearing cloth, clearly audible over the rush of freeway noise.

Now that she's down a bike, she needs to take control of this vehicle and that's going to mean injuring people. Should be possible to do it nonlethally, at least. She whacks the guy grappling her with her shield. (4 damage)

The giant clearly felt that, but he's still in the fight.  You did at least inspire him to switch tactics: now he's trying to crush you in a still-increasingly-enormous bear hug.  It doesn't particularly work, though it might well have hurt a normal person.

And then suddenly you take nine damage as something hot and sharp careens off your skull, and, ouch, twenty six more damage as a second one sticks in your upper leg.  Thanks to the wind rushing out the back of the van you can't smell yourself cooking, but it still stings.  A third projectile skims off your armor and sticks in the van's ceiling.

This is starting to add up. She twists in the grapple enough to get eyes on the flier and throws a Holy Smite at them. 

The giant seems to know what somatic components are.  He tries to lift you up and slam you against the wall of the van, and comes dangerously close to tipping you both out the back, but can't stop your gesture in time.  The flier is enveloped in a sphere of brilliant light...

...and immediately pops out again, still pursuing at freeway speeds, seemingly untouched.  She -- you're almost sure it's a she, through the shrouding flames -- takes another cautious shot with her orbiting arsenal, but it lands a few feet short of the van and ricochets off to the side somewhere.

Maybe she's got spell resistance. Maybe she's Good. Maybe she's Good and enchanted and baiting her in closer will help, but she's not seeing a good way to do that. Maybe now that the crashing-her-bike ship has already sailed she should just teleport out and make this someone else's problem, except if the flier's enchanted that could go really badly for them. 

She whacks grappling guy with her shield again, less effectively, and says, as conversationally as she can while breathing hard and trying to be heard by the flier, "I still want to know what you think you're accomplishing here!"

You have to shout to be heard at all: between the highway winds, the flier's dozen's of spinning projectiles, and the crash of your poor motorcycle careening off the barrier, it's gotten pretty noisy.  But the giant still hears you, and snaps back, "saving the world", as he slams you into the wall of the van again (2 damage).

Then from the driver's seat there's another voice, thick with exasperation.  "Don't banter with her!"

Saving the world? From what? Oh. "Killing me won't stop the gods from intervening! It will just stop me from healing people!"

"We can - " "DON'T!"

The giant looks like he's thinking of arguing some more -- it's not clear with you or with the driver -- but then one of his colleagues interrupts by shooting you in the foot (9 damage).  He's using a different, smaller gun than the long rifle he was firing before, but in the confines of the van it's still enough to rattle even your eardrums.  The giant flinches, and starts to topple out of the van.