In theory, Tobirama should have been more than strong enough to handle this mission on his own.
Hashirama had gotten intel that the person Konoha had been hired to hunt down had some strange and unconfirmed ability to disrupt chakra sensing, though, and had then proceeded to worry and nag at Tobirama until he'd agreed to go with a partner. And that partner then just needed to be an Uchiha, to show how well the members of their alliance could work together now.
Tobirama will never admit it outside of his own head, but it was probably a good call. He and Izuna know each other's fighting styles so well that it was surprisingly easy to slip into working together, and the target is proving to be a slippery one even with the two of them working together to pin them in place.
Izuna is the faster of the two them in short bursts, and they don't need to share more then a sideways glance before he takes off to try and circle their target from behind. Tobirama suspects that they know the landscape better than either of them. Tracking them through these unfamiliar woods had been difficult to begin with, and they’ve given the two of them the slip more than once.
This time they'll be forced to flee either towards a river or an open clearing where Tobirama has already scattered a web a hirashin markers. He's ready to put an end to this.
He waits crouched in the underbrush, senses stretched and muscles taut as they bob and weave through the trees as they try to dodge the Uchiha after them. The moment stretches, Tobirama does not move until -- there. They turn and Tobirama turns with them. A hooded figure breaks from the tree line and makes to cross the river.
Before they can step foot on it, Tobirama finishes the jutsu he's been holding. The water falls out from under their feet as it rears up to form a dragon. They stumble down into the riverbed, turn to find a way out only to be blocked by Izuna bearing down on them with his blade.
He can feel the surge of panic in their chakra, the way it coils in as they slam their hands together in a sign Tobirama does not recognize.
The whole world seems to buzz, but Tobirama feels it most strongly in his teeth. Even his chakra resonates with it, and it causes him to lose hold over his on jutsu. The water he had been holding crashes down all at once, neither Izuna nor their target is able to keep their footing.
Izuna has far more practice a situation like than the average shinobi though, and Tobirama's assistance as soon as he sucks in a breath and gets his chakra back under control from whatever technique that was. Hopefully Izuna can take them alive. He would very much like to study it.
Izuna does recover faster, darting out of the water and grabbing their target by the scruff, then catching their arm in a hold when they try to turn on him. Tobirama has closed the distance by then, he sees the opportunity to pin them with a seal tag. When he reaches out, he recognizes what's happened in the same moment Izuna does.
For a brief moment, he doesn't recognize his own hands, so pale that they're nearly while. The technique that disrupted his jutsu disrupted his seal as well, the truth of his coloration suddenly bared to the world.
Izuna's mouth falls open, sharingan eyes looking up and finding what Tobirama dreads that he will.
"You're --" He cuts himself off as the shinobi under them uses the slack in his grip to kick off of him and dart away.
"Focus!" Tobirama barks. He isn't so distracted that he lets it happen without consequence -- he stabs a kunai deep into their thigh. They cry out and go tumbling beneath the choppy river waters again.
To his credit, Izuna recovers quickly and grabs their cloak before they can swim away too far. He gets pulled halfway into the water for his trouble, but he's stopped their momentum enough for Tobirama to drop beneath the surface himself. He deflects their reactive strike, Izuna catches their other arm from behind, and he finally pins the tag to their chest. They go stiff and still and Izuna hauls them back out of the water before they can begin to drown.
Tobirama surfaces too, flicking the excess water off of himself with a gesture. Izuna's eyes flicker up to look him over again, and so Tobirama determines that he's too distracted to properly secure their target. He grabs them around the waist and hauls them to shore in his stead.
The tag seems to be holding, but given that they've proven able to disrupt other seals, Tobirama is disinclined to trust it.
"Izuna, your wire."
He cannot see him, but Tobirama can feel Izuna's chakra flare in surprise behind him. His knees hit the rocky shoreline next to him half a beat later and with far less grace than Tobirama would normally expect from him. He moves jerkily as he secures their target at the wrist, as though afraid to accidentally touch Tobirama.
Ridiculous. Tobirama scoffs and checks his Izuna's work after him since he's not in a state to be trusted right now. The Uchiha visibly flinches at the sound, turns away shame-faced. One of his hands reaches up to rub at his eyes as though the sharingan aren't famed for perfect clarity.
Tobirama slaps his own hand to his shoulder and pulses chakra through the seal there -- it's still functional, it's only the flow of chakra through it that had been disrupted. His skin tans before his eyes.
He considers, for a moment, pretending that this never happened. From what he has gathered from Itama, whatever strange compulsion that has the Uchiha gathering people with red eyes is based on some kind of religious doctrine, and as such those they take in are afforded respect. Izuna may hide the information in order to prevent Tobirama gaining any sort of influence in his clan -- But no, based on how intense Izuna is watching him right now it would be better not to rely on a prediction of Izuna's behavior based on information gathered about him before he knew.
"You will not say a word about this to anyone." Tobirama commands. His heart beats so hard he can feel it in his throat. If they try and take him and hide him away he will -- he does not know what he will do. He cannot allow himself to be the cause of this peace they've built breaking the same as he cannot just hand himself over.
To his surprise, Izuna does not put up even a token argument. .
"Uchiha."
Izuna bows his head and keeps it lowered. It is likely as close to agreement as Tobirama is going to get.
So Izuna is probably going to have to pluck out his eyes and go live in the wilderness as a hermit.
Tobirama keeps glaring at him. He hasn't offered to pull the water out of Izuna's dripping clothes, nor has he made any indication of letting anyone but himself haul the prisoner he has over his shoulders back to Konoha.
Izuna doesn't ask. In fact, since the Senju -- ugh, can he even keep calling him a Senju? -- keeps glaring at him, Izuna makes the decision to stop glancing over at him at all. It's not as though he can forget what he's seen.
Look, he's been through this all before alright? Adorable little Itsuki was actually the terror that turned out to be Itama, and trying to kill his family might only be forgiven because it was done out of ignorance. And it was a clan-wide thing that happened when he was a kid, so everyone was pretty much willing to share the blame on that one. The issue of Tobirama is not clan-wide.
He tries to count up in his head just how screwed he is. He loses track of the amount of times he's wounded him somewhere in the hundreds, and doesn't even know where to begin starting to count the number of attempts. Maybe he can argue that they only castrate and exile him instead of burning him alive? Though that will involve promising to make reparations to Tobirama and is that really any better?
... Okay, it's probably not that serious. Tobirama would have to be liked by his clan and demand such a thing for that to happen, and while he might do the latter, the former will stop him from the worst.
"Uchiha." Tobirama snaps again, and he didn't even do anything besides sigh and brush back his hair. He stops and Izuna almost loses balance when he does too. Suddenly he finds himself dry as all the water still soaked into his coat is flung to the ground with one sharp hand sign.
"You're overthinking things." Tobirama tells him, voice still so tense. "The mission will be a success. Nothing else needs to be mentioned about today."
There is a muffled grunt from the person still over his shoulders that they both ignore.
"Uh -- right!" Izuna agrees. One more lie is probably not going to make things any worse for him, right? And there's no way he's letting everyone else go around and lose favor with Amaterasu on accident. "Of course!"
Tobirama does not look very convinced by his chipper attitude.
"I will defend myself if someone tries to take me." He warns.
"Obviously." Izuna agrees. So that's also going to be a whole other mess to deal with.
"Hm." Tobirama says. He turns to continue towards Konoha with one lingering, unhappy glance Izuna's way. He sighs and follows along, and starts thinking about where it would be nice for a blind man to live this time of year.