My guess on the online difficulty is that all the steps would need to happen in the same instance of the End of Time. Being in a party and having one person be an anchor for the instance may work in that case
Just got this to work online. followed your process. went to the caverns in ancient era and traveled back and forth through the ruined portals until I got a water shrine. didnt seem to work the first time so I found another one in the cavern and did it again. waited a bit and went around the map doing other stuff and it just completed for me when I returned to the end. LETS GO!!
I got my lost spriggan to sprout on legacy online. I collected sapling, plant it on fertile soil in the end of time area, then grabbed a mana shrine (from an arena) and let it expire by the fertile soil area. it didnt sprout right away. I left the area, did a bunch of monoliths, log off, then did some more monoliths. when i went back to end of time i could no longer click the fertile soil area. I though i had to grab another sapling but i just left area to refresh, then lost spriggan is there! thank you for sharing this easter egg.
I think the reason it does not work in online mode is that water shrine effect disappates when you change zone, you still have the icon with the timer but not the effect.
Hey , I noticed you don’t have the missing life/ward per second affix on your Rive HH paladin , have you changed the build ? No ward ? Or you generate ward with attunement only ?