I´d also love to see a tier(advancing) system that encourages group play.
I think they should handle it like WoW did:
A titan of your current tier should require at least a group of 10 people(like a raidboss in WoW) but if you advance one or two tiers, get the corresponding equipment and skills and then come back to the titan of the previous tier you should be able to solo it.
Same goes for the
but only with 3-5 people required.
The reasoning behind this?
Well, If you can solo everything and there is no need for grouping this game could as well be called Oort Offline.
Also, like already adressed in @Zouls “holy trinity” post (and many others), there may be dedicated classes and if you are dedicated tank you may have enough defense to survive the titans attacks but lack the damage and heal/sustain that is needed to survive his attacks long enough to kill him alone. The same goes for dedicated damage-dealer (lack of defense and sustain) and dedicated healer(lack of defense and damage)