Nexus Seige and new possibilities

Let me preface this by saying I am a TF2 player at heart, and whats more an engie player at that, so seige/defense gameplay is par for the course for me, and I may be biased to the idea of the attack/defense format.

I like the idea of different items and buffs for teams and different goals, as in most games it comes down to one team desperatley turtling hoping for the ahead team to throw or eventually win while the other team pushes in and slowly chips away at the behind team to get an opening. Dedicating an entire new gamemode to this idea seems logical and initial testing is showing no distinct advantage either way. Sure defense teams may end up with heimerdinger and make mid an unmovable wall, but then you have top and bot to worry about, and the offense has cannons that outrange the defense and this and that. Defense has a zhonyas for their towers, and an infini flash zone, so its not a clear one side advantage deal. However, I have been unable to do any testing further than PBE so who knows what will happen in live, and I'm not making this post to say its balanced and good, I'm making this post to suggest a few lore event scenarios. I only suggest these to prevent cliffhangers like the bilgewater event (still loooooved that event). The freijlord got a legit ending to their power struggle, their arc is still open but as of now they reached a logical ending, with Ashe as queen.

The seige of Bilgewater: Gangplank has finally amassed a force of loyal fighters large enough to challenge the new rule of Miss fortune. He and Illaoi charge MF's ship in a mass boarding party and attempt to cut down the uprising to remind the town why Gangplank was the tyrant to begin with. Miss Fortune, Graves, and Twisted fate fight to hold off the attack and possibly finish Gangplank off and make sure he dies for good.

Noxus and Demacia: Swain and Darius have found a way to assault Demacia from a weak point in their bulwark. They take the army, Sion, and Urgot to attack the city and force the city-state to finally submit to Noxian rule. While being seiged, Garen and Shyvana find a way to sneak a contingent to Noxus and attempt to hit them while their entire force is distracted with the seige of Demacia. When they arrive they find Talon, Leblanc, and Katarina waiting for them as Swain predicted the counterattack, the race is on to either bring Demacia to it's knees, or force Darius to surrender by striking Noxus at the heart.

Wrath of Icathia: Kassadin has grown content in recent times as Malzahar's efforts were seemingly weakening over the years. Unkown to him and the Preservers, Malzahar had been studying and performing rituals at the ruins of icathia and has finally found a way to spill the void into Runeterra. Caught off guard, the void has already corrupted much of the land including Piltover, Zaun, Bilgewater, and the freijlord. One of the only areas to stay unaltered ironically is Shurima, kept safe by the efforts of Nasus and Azir, therefore the preservers fall back to Shurima and stage a defense there. They hope to gather strength and push the void back before Cho'Gath grows powerful enough to destroy them all, or even worse, Kog'maw's "Daddy" finally arrives.

The fate of Shurima
With their influence and power growing, Nasus, Azir, and Sivir have taken it upon themselves to finally try and bring Xerath and Renekton in for trial. Nasus hopes they will find a way to save his brother, but before they can find where they are, they attack the new capital city of Shurima with a force great enough to conquer and remove Azir from power. Nasus and Azir must form a defense as quickly as they can to prevent everything they've worked for from crumbling away like sand.

The fall of Zaun: The people of piltover have been in unrest after experiments by Viktor and Singed have become more and more dangerous for the people of the city of progress. Even worse, Viktor has been kidnapping citizens to forcefully augment them into his glorious evolution. Jayce, Vi, and Caitlyn amass an army to clear out Zaun's influential figures and bring law to the lawless town. Zaun's biggest scientists enlist the help of Warwick and Twitch to push the pilties out and possibly capture victims for their twisted experiments. Both form their plans but neither could have predicted Dr. Mundo and his force against both.

The rumble in Bandle: Rumble's latest work in Bandle city have become renound, but unrefined. Heimerdinger actively speaks out against Rumble's reckless practices, but Rumble ignores him and lables him a human loving sellout. Heimerdinger launches a campaign against rumble, but rumble, being very tempermental, assaults the college Heimerdinger is at. The bandle gunners and scouts come to the scientist's aid as Rumble and those to agree with him such as Ziggs and possibly Lulu join in the attack. the attack brings tension and change in Yordle/human relations and possibly the downfall of great yordle minds.

Skin ideas: These events could bring in new skins as well, but its just an idea not a guaruntee, just like this entire post actually....

• Tyrant Gangplank & Rouge Miss Fortune (and vice versa if MF wins.)
• Brutal Darius (name WIP) & Defeated Garen/J4/Shyvana/etc.
• Risen Malzahar & corrupted (or surrendered some varient of that) Kassadin / Cleansed Malzahar & avenged Kassadin
• Risen Nasus/Renekton, Purified Azir, Imprisoned Xerath / Fallen Nasus, Exiled Azir, tyrant Xerath/Renekton
• Zaun/Piltover event would be less for skins since alot of their themes are meant to oppose each other, but you could think of something.
• Professor Heimerdinger (his outfit the day of the attack) & strike force Rumble, making this the theme for the sides, professors vs. the revolt.

I understand altering SR for each region would be difficult, but for Riot, it would be doable. Besides, this is just an idea which I really don't expect to actually come to fruition, but still let me know any other ideas for siege events below.