What game change would you suggest?

[Rygar]

Call of the Zero on raid targets, no question.

Other candidates:
Nerf Insta-Click agro items (too easy for warriors to hold agro, shits on classic experience)
Make Eye of Zomm non-agro (make pulling classic)
Nerf Fungi Tunic, too OP
Charm change (Mob gets a 15 second rage buff after charm break, can't be mezzed / re-charmed / stunned / rooted until buff is gone)
Scout Charisa / Lodizal randomized spawn points (+timer variance for scout)
Implement quests / specific vendors for recharges
Disable MQs worldwide
Ring of Vulak event (I'm unfamiliar with it really, but sounds like a lot of raiders would enjoy the challenge in this era)