Mitsuru and Rias were making short work of their area. The devil's wings and protective magic prevented anyone from getting close while Mitsuru defused each device in turn, eagerly pocketing them for later study. Her mind raced with possibility. If these contained even rudimentary technology from the invader's world, she could easily integrate it into her own systems and transform her ability to develop and simulate new equipment practically overnight. It could even pose a solution to the quandary she had faced in developing the permanent doorways that would remove the limit on the number of people who could come through from other worlds.
"We'd better hurry. I think the police are coming."
Mitsuru removed the next bomb and smuggled it into her bag. With that done, they spilled outwards onto the main avenue, carefully avoiding the areas where the police had deployed to protect the sites. Your explosive entrance a few blocks away had sent them scrambling to respond, leaving gaps for her and Rias to exploit.
"You have a big smile on your face, Mitsuru."
"I'm thinking of all the things I can do with these components. I can't wait to crack them open!"
"Just remember to disarm the explosives first, please."
Rias felt something. She wasn't certain of what it was – but years of learning how to fight had given her a sixth sense for this sort of thing. Thinking quickly, she tucked her wings close to her body and dived through the air with Mitsuru in her arms. The trajectory with which they were travelling a few seconds ago was struck by a precise beam of energy just moments later.
"W-What are you doing?" Mitsuru cried as her stomach did a somersault. The fact that they were under attack didn't occur to her. Rias covered as much of her body as possible, smushing Mitsuru's face deep into her DD bosom. Landing on the ground, Rias swivelled on her heel to face the attacker. It was Sundar – back to cause trouble again. Mitsuru ducked for cover, peering over the edge of a concrete tree planter.
"You again!" she cried.
Sundar sighed, "I had hoped that none of you would have dared interfere in our plan – but it seems that was too much to ask."
"Of course it is! I'm not going to let you kill someone with these things!" Mitsuru yelled back.
Sundar shrugged, "But I guess this is what they call a happy coincidence, huh? The Doctor's been running himself overtime trying to figure out how to stop you. But here you are, in the flesh! Meddling with my plan – with one of those damned devils by your side. I was already planning on killing you, but you just made my job so much easier."
Another blast of energy shot from his outstretched palm, only to be blocked by one of Rias' magical vigils. She scowled and stepped in front of Mitsuru, "Don't forget about me. I'm not going to make this easy for you."
"One devil isn't enough to beat me," Sundar boasted, "Even the ruin princess herself. I'm not a bumbling moron like some of my other compatriots."
Mitsuru yelled, "Rias, don't do anything reckless for my sake!"
Rias was already resolute in her decision though. The gauntlet had been thrown down, and she was faced with a difficult situation. On her honour as the future head of the Gremory clan, she couldn't simply abandon a friend like Mitsuru. She'd protect her or die trying, after all, Mitsuru was the one who introduced her to her fiancé. That was a debt that would take a lot of time to repay and Rias intended to fulfil every bit of their informal contract.
Even more than that – Mitsuru needed to live long enough to tell you how she really felt. There was nothing sadder to Rias than an unrequited love. A world where people only choose one partner was foreign to her, a social expectation that seemingly only existed to make people unhappy. Why not have multiple lovers if you were mature enough to handle it? It didn't make any sense.
Rias mustered the ruinous magical energy that flowed through her body and fired a bolt of red-black lightning at the invader. Sundar tanked the blow without moving or making any effort to defend. A dust covered form glided down to the ground, and as the dust settled it was clear that he had only suffered minor cosmetic injuries for the hubris. He laughed and dusted off his collar, "Is that all? I haven't even gotten serious yet."
Rias growled, "Neither have I."
Mitsuru squealed and hid behind the barrier as even more dark energy surged forth from within Rias' body, indiscriminately shattering windows and scorching whatever was unfortunate enough to be within its path. Rias had held back on her previous assault, to give him a chance to turn and run away – but it was clear he had genuine murderous intent. She had to take this seriously, or Mitsuru would be in real danger. He motioned to himself as if to invite yet another front-facing assault.
Rias was too polite to turn down such an invitation. She lifted her left arm up into the air and summoned an amplification circle in front of her body. Both arms came together and pointed at Sundar, the surrounding energy being pulled back in and forming a violent whirlpool in the air. Rias concentrated everything she had on a precise and extremely destructive attack. She didn't hesitate to unleash it.
The stone and brick beneath were torn away from the ground, being flung upwards as a set of deadly projectiles. The sound was deafening! Mitsuru covered her ears as a terrible rumble rang out through the district. For a brief second as the large beam of black energy surged towards him, Sundar believed that he may have made a miscalculation. He was forced to quickly bring up his defensive shield system lest he be blown away.
The beam passed over him and completely engulfed his body. The HUD installed into his left eye displayed a worrying drainage rate for his personal shield. Tick by tick, he could feel the heat and energy growing more intense. His heart pounded as he counted down the seconds until it would break, and break it did. Just as Rias finally ran out of energy - it shattered and exposed him to the full brunt of her magic. It was only momentary, but it hurt.
Sundar staggered back. His body was covered in sooty burns, and the armour he wore glowed red hot from the heat of Rias' attack. "Ah! What an embarrassing miscalculation," he griped, "I took you too lightly. That was a real attack, huh? Trying to kill little old me?"
"You're threatening to kill Mitsuru – don't get upset when I respond appropriately."
"Heh! All this for her? You don't know the first thing about that girl. If you did, you wouldn't be so eager to defend her."
"Oh? And I suppose that you do?"
"More than the likes of you could hope to understand. But it would be a waste of time to share it with you. She's already bought your loyalty, hasn't she? It doesn't matter what evidence goes contrary to your image of her!"
Rias fluffed out her hair, "Why would I believe a bastard like you? Stop talking and start fighting."
Sundar's frown grew even more furrowed. He snapped his fingers and teleported in front of Rias so quickly that she didn't have time to react. She felt her feet leave the floor as she was flung several feet into the air by a nasty gut punch. She flared her wings and corrected herself, coming back down at him with several smaller bolts of magic. He dodged most of them, taking a glancing blow against his left arm due to their number.
Again, he teleported in to close the gap and punished Rias with a roundhouse kick. Rias' wings couldn't correct her momentum this time, and she found herself flying through the glass window of a nearby office building. Sundar neglected to attack Mitsuru now that she was gone, instead choosing to chase Rias and finish her off. It wasn't like Mitsuru could get away with those stubby legs of hers.
"I guess I underestimated you, ruin princess! But it still isn't good enough. You know, people who make me put in a lot of effort really piss me off. You just come out here and get slaughtered, and I'll consider making it quick!"
Rias did not consider that a tempting offer. She had used so much of her magic teleporting back to the district, and even more of it attempting to blow her foe away. She could only keep this up for so long before her defences failed her. He held all the cards, he could even go back and threaten Mitsuru to force her into an awkward position. She couldn't keep hiding to recover her strength. That meant that the only option was to go on the offensive!
Rias condensed the power of destruction into the palm of her hand and swept outwards from her hiding place, pointing the continuous stream of small, baseball sized shots into Sundar's back. Each explosion only further his confusion and ate away at the surrounding area, destroying the floor and ceiling completely. Sundar moved away and scrambled for his own hiding spot lest one of them hit him directly. Sundar laughed deliriously, "Haha! This black crap is eating straight through my armour! I guess he picked you for a good reason, and not just those stupid boobs of yours!"
Sundar looked down at his chest and winced at the large hole that her power had chewed through his second layer of physical armour. Not only could it knock out his shields in a second flat, but it annihilated whatever it touched on a molecular level. One wrong move could be the end of him. His pride wouldn't allow him to be beaten by some two-bit bitch summoned by a human.
It was a good thing that the Doctor had prepared him for this kind of battle. He needed to switch strategies. Rias was trying to protect her fleshly, unpowered summoner – so that meant if he could get outside and reach her… Rias' heart skipped a beat as she saw Sundar running to the shattered windows. He was trying to get away!
"Stay right there!" she demanded, sprouting her wings and flying after him. He was already bearing down on the wide-eyed scientist. Rias didn't have time to think. She dived towards them and put her own body between her and Mitsuru. The barrier she erected was too weak, she immediately felt it beginning to crack under the strain as another energy attack tried to force its way through. If it hit Mitsuru, she would almost certainly be killed. Rias hunkered down and refused to move, no matter what the consequence may have been.
Crack!
All at once the shield gave way. Rias covered Mitsuru with her body as a violent explosion ripped through the area and engulfed them in a cloud of smoke. Sundar gloated happily from atop the planter – believing that both women had been killed in one stroke. That was until he saw a pair of figures staggering into a nearby building through the cloud of rubble.
"You can't get away from me!"
Mitsuru was in a blind panic. Rias was injured badly by the last attack, and her magical power was being constantly drained by Sundar's assault. There was blood all over her lab coat, the foolish girl had decided to take the full strength of his attack, and for what? To protect her? She found a hidden nook amongst the building's tall shelves and stacked wooden boxes, laying Rias down so that she could rest for a moment.
"What the hell are we going to do now?" Mitsuru despaired. She couldn't fight like Rias could, and you were the one with the Sledgehammer. Summoning someone else would mean having to compromise with one of the defusal teams. Mitsuru was not willing to risk other people's lives for the sake of her own.
Rias spat the blood from her mouth onto the floor, "Give me a second, Mitsuru… just give me a second."
"Why did you do that? Stupid!"
Rias smiled, "Because you're my friend."
Everything stopped.
Mitsuru repeated the statement in her mind; "I'm your… friend?"