Alexander Questline Question

[Necrotica]

But it still doesn't work even if you ignore point of origin for Alexander.

Summoned/Travels back in time. It is now physically there. The summoners are killed by the illuminati. The cut scene then shows it disappear and travel/return to 3 years in the future. What was left behind for people to discover and go inside of to start the loop?

[Iscah]

But it still doesn't work even if you ignore point of origin for Alexander.

Summoned/Travels back in time. It is now physically there. The summoners are killed by the illuminati. The cut scene then shows it disappear and travel/return to 3 years in the future. What was left behind for people to discover and go inside of to start the loop?

In the present day, prior to the summoning, there are Sharlayan ruins in the lake. (From memory it was referred to in passing as a "defence mechanism" or something like that.)

The Illuminati (guided by Backrix's lost journal) summon Alexander into the structure somehow, and it emerges from the river as we see in the initial post-credits cutscene.

It briefly teleports back to three years ago, where Mide thinks she's summoned it and raises the barrier to seal it away – but then it vanishes back to the present time and nothing else is left behind to see.

In any case nothing needs to be left behind from the earlier "summoning", which wasn't a summoning at all. The Hotgo group intended to summon Alexander but were interrupted by the arrival of the Illuminati-summoned Alexander arriving from the future, and thought it was the result of their own work.