Embalming is not something typically used in the Senju clan- they are shinobi of the Earth and often prefer to return to it after leaving this world. As strange as it might seem to the other clans, it is often a comfort to see the deceased bodies beginning to fail at the funerals. It means that they are becoming one the earth- that they will remain as dirt for their kin to live off of. They will continue to serve their clan by offering nutrition for future crops.
To embalm a body means that it will take far longer for the body to return to the earth. It will remain for years- slowing the process of their true end. It was nearly unheard of for a Senju to be embalmed, but no one had objected when they had read it in Tobirama's will. For that, he was grateful.
It meant he didn't have to find an excuse as to why he was so serious about being properly preserved. It wasn't as though he could tell them the truth- that he wanted his body in good condition in case the seal was one day activated.
He could still revive without it, of course, but it would make the process a lot longer and uncomfortable. By embalming his body, he wouldn't have to wait for the dirt and water to nourish him from the bone out. That would take nearly a year. Since he was properly preserved, it made things a lot easier.
It only took a month for the dirt and water to push in through the pores of his skin, nourishing his body as it built him up, layer by layer. He was crafted fully from flesh to bone, slowly and steadily. The last pieces of his body to be brought back were his organs and nerves, the Senju having specifically designed it to be that way. He'd much rather avoid having to feel any more than necessary.
As such, when he felt his mind slowly hazing back to life from the darkness, he had been grateful for his foresight. His eyelids had opened carefully, the effort required not going unnoticed. The Senju felt his fingers testingly grip the hardwood of his casket, his arms aching at the energy it required.
His chest heaved inwards as a dry cough left his chest, the resurrecting shinobi's arms falling back to his sides as musty air filtered into his chest. The dampness of the muddy water that had snuck into the casket felt increasingly suffocating, his lean muscles reflexively shuttering as he tried to control his breathing. He didn't need to waste all his oxygen by panicking.
His body ached, the man taking a careful breath as he began to gather himself. His body was sore, so he supposed it must have just finished the bulk of the seal's process. His body was ready, though his nerves must be receiving the finishing touches. Tobirama, unfortunately, couldn't check due to the lack of light in his casket.
So, instead, he settled on letting the scroll finish its work, the Senju idly moving his fingers and shifting as much as he could in an attempt to help wake the previously destroyed nerves. He made a point to stifle his chakra as well as he could, not wanting anyone nearby the feel his awakening. That would cause more problems than he would like to deal with.
Tobirama focused on stifling his chakra and awakening his nerves, refusing to acknowledge the issue of the casket's stench. He knew the more he focused on it, the more it would be an issue. Still, he found it hard to ignore the sickening reek around him. This was what happened when you put a corpse in a box and stick it underground for a few decades, he supposed. He had known he wouldn't be waking up to the smell of roses, but still. He hadn't known it would be this bad.
As he tried to ignore the urge to hurl his guts out, the man felt his body coming completely to life. He could feel his body's soreness enhance, his skin feeling as though it were on fire, though he supposed that was what happened when dirt and water pressed its way into each pore. It was excruciating- not only the process, but the slowness of it all.
He didn't know how long it took. All he knew was that the total time of the revival shouldn't take more than a month. Which was what made it so hard. He knew it wasn't as long as it felt, but each second felt like torture. Each moment he stayed in his casket, healing, was another moment for the Uchiha to do whatever the hell they had planned. He needed to get to the village as swiftly as he could.
With this in mind, he willed himself to move. His nerves seemed to be refreshed, so the only thing holding him back now was the ache in his bones. Unfortunately, that was unlikely to disappear anytime soon. So as he lifted his hands to push the casket open, he was prepared to get going despite the soreness.
His heart skipped a beat as the lid of the casket didn't move, a moment of realization crossing Tobirama's mind. Right, he was six feet under. He had a lot of earth above him that he would need to break past if he wanted to get to the surface. His brows furrowed as he forced himself onto his stomach, taking a few deep breaths of the revolting air. He needed to get out before he ran out of oxygen. The seal had finished its work- he was just as alive as he had been all those years ago. Which meant he needed to breathe just as much as any other living being.
Taking a calming breath, Tobirama rammed his back into the lid of the casket, fingers clenching around the watery dirt that had made its way into the casket over the years. He was momentarily glad that he had been buried in his armor, otherwise, this would probably hurt a lot more than it already did. He was going to have to take it slow and steady if he wanted to get out of the casket without heaving in too much oxygen at once.
So he found himself counting in his head, staying as composed as possible in such a situation. He thought with a steady rhythm, 'One, two, three, four, five-' THUMP 'One, two, three, four, five-' THUMP, continuing on despite the distant question of its effectiveness. Distantly, he could feel the bits of dirt that had made its way into the casket over the years, fingers digging into the familiar soil of Konoha. With each thump, his chest filled with a renewed source of death-filled air. It was one thing to smell the fresh stench of a dead carcass, he realized, but it was another thing completely to be in a box that had been building it up for years upon years. Had he been a lesser shinobi, he might have admitted to the gag welling up in his throat with each thump. He needed to get out of this terrible place.
It took some time, but eventually, he felt something hit the back of his arms. A thin smirk of satisfaction found its way onto his previously frustrated face, the silver-haired shinobi turning onto his back once more with a huff of effort. He settled a hand on his chest, feeling the rapid thumping of his heart as he tried to steady himself. He was beginning to feel light-headed, much to his rising panic. He had to do this the right way, otherwise, he'd only succeed in suffocating or burying himself into the dirt once more. He couldn't afford to die a second time- not so soon after the Uchiha had been acting suspicious enough for the seal to activate. He needed to get out; he needed to be at the village's aid as soon as possible.
Using this as his motivation, he pushed against the lid once more, lifting it just enough to give an opening. He made sure to open it just enough for an opening; only a bit of dirt crumbling in from the side of the opening.
His hand moved, silently cursing the darkness as he began pressing his hands flat against the dirt on the side, compacting it. He smoothed both his hands over the earth, his back holding up the lid of the casket despite the protests of his spine. He pressed the soil as well as he could, gritting his teeth at the labor it required.
Bit by bit, the soil settled into place. Soon, he had a smooth wall of dirt by his side. Now for the risky part. He needed to get up to the surface, but he couldn't just break through six feet in one swoop. He didn't have the brute strength of most Senju. He had to work smart. Luckily, this wasn't too much of a challenge. He was used to needing to play tactician to get through things. Today was no different- he was sure he'd manage.
Using this thought for motivation, he began using his fingers to carefully dig into the dirt. His chest felt tight as he did so, the silver-haired Senju resisting his natural reaction to tear into the wall. He blinked as his eyes pulsed despite the darkness, closing them tightly. He was Tobirama Senju- he could do this. He would escape and aid his village. All he had to do was dig one measly tunnel towards the surface.
Fingers moving shakily, he began to dig. His nails scraped against the soil to the left of his casket, the man moving the dirt to rest at the bottom of the wood. His lungs had begun to burn, so he focused on taking steady breaths. He could feel his eyes glossing over, which he assured himself was a result of the slowly occurring suffocation. His hands moved quicker as his mind moved on its own, finding it hard to follow his own logic as the panic crept into his skin.
He repeated his goal in his mind, hoping to will his body into listening. 'Make a circle beside the casket to crawl into. Make a tunnel to the left to crawl out of. Use your hands to flatten the sides of the tunnel for stability.'
The shaking in his hands became more apparent even to him, the Senju trying to shake it off. He could do this- he was a man of legend, damn it! He refused to die of suffocation. He blindly stumbled to smooth the circle he had built around himself, carefully crawling into it.
At least he was one step closer to being away from that horrid smell, he encouraged his sluggish mind. His hands moved to scratch to the side of one of the walls, the man's movements not nearly as coordinated as they had been only moments ago. He willed himself forward, reminding himself, 'For the village, for the village!' as soil crumbled from his upper left and into his hair.
Bit by bit, he carved out his tunnel, calloused palms clumsily pushing the walls into place. His chest heaved with the effort it required, lips curling into a glower despite his best efforts. Slowly, the dirt tumbled past him and into the casket below. He blindly dug, eyes clenched as he pulled at the earth. He was almost there, surely! He had never been one to act on blindly positive thoughts, but right now, he needed them. He'd never admit it, but he almost wished Hashirama was with him. The brunet would probably spout some overly-simplistic encouragement right about now.
He could practically hear Hashirama's praise as he felt his fingers grip at the next bit of dirt, his fingers swiping through the wall with none of the normal resistance. Tobirama allowed his lip to curl into a satisfied grin as light filtered in through the hole, burning his eyes. His body ached as the sun hit against his deathly-pale skin, oxygen rushing into his lungs as he finally allowed himself to hack out a nasty cough.
His arms gripped onto the side of the hole he had dug as he let his body lurch forward with each hack, steadying himself. He still felt a bit light-headed, but he didn't hesitate to crawl out of the stenchful hole, laying his body against the dirt as the sweetness of the fresh air swept through his chest. He gave himself a moment to regather his composer, fingers gripping the soil as he laid his head to the ground, eyes closed. Fuck, he was going to kill those damn Uchihas.