Guild Wars 2

little hint:
You don’t need to forge the infusions you can simply buy them in the FotM-Lobby for 75 (defensive) or 225 (defensive or offensive) FotM-Tokens.
And the Back-Slot Item can be bought for 1850 FotM-Tokens and 24 Skill-Points
There would be your Twilight

And on a side note: As someone who farmed the 250 Powerfull Blood, there are better spots than the Trolls to farm it. You just need to look around

Guanglai Kangyi.4318:

People solo dungeons all the time. There are videos of a melee warrior soloing Arah. It takes him like half an hour to kill Lupicus but he does it.

AC is soloable. There are some parts that might be annoying but it can be done I’m sure.

For Arah, I’m calling BS
Why? Cause 3 ways are impossible allone and the only not-impossible way is Path 2 and I doubt anyone could fight his way through the Spider-Cave or run through it as a warrior.
(Way 1 needs 4 people to clog the tar-geysirs, Way 3 needs atleast 2 people to carry those Orb-thingys and Way 4 needs 5 for the High-Priest of Grenth)

For AC: Show me a video and we can talk

Well, Ascalonian Catacombs are in my opinion the easiest Dungeon in the whole game but:
There are events (not bosses) you propably can’t solo, on Path 1 the breaking Point (atleast in my opinion) would be the event with the six Burrows you need to destroy simply cause you can’t stop both “lines” of borrows.
Path two, the trap-part is impossible cause you can’t use the traps allone
Path three is propably the easiest to solo (if you are an Elementalist) because the only true problem would be the event in the lovers room and with Staff Fire 5 and Frostbow 4 it might be possible. Every other class? I don’t think so.

If you want a challange, two-man the dungeon, it’s fairly easy (done it on all three paths) and still a challange.

I highly doubt that your human elementalist can weapon swap, no elementalist can.
Elementalists and Engineer are the two professions (as far as I know) who can’t weapon swap.