I'm wondering what boon these achievements would grant. I think they should be more than purely ornamental. For example, perhaps the harder-to-accomplish achievements should give the player back an action point (if they had spent one already). Or would allow them to spend second wind as a minor action (or free action if dwarf). After using the boon, the achievement would become void for the adventure.
Cold as Ice - Roll three successive critical failures on attack rolls (boon: reroll one attack before the end of the encounter)
Such a Disappointment - You make more than one attack in a round and miss with all of them (boon: you get to make a basic attack as a free action) [note: you can only achieve this once in an adventure]
Just a Fleshwound - You take more than your bloodied value in damage from a single attack and do not fall unconscious (boon: spend your healing surge as a minor action, or free action if you are a dwarf)
Dangerous Companion - You deal more damage to allies in an encounter than you do to enemies, including any damage done while dominated (boon: you can spend your second wind and an ally of your choice regains hit points instead of you)
The optimist believes we are in the best of all worlds. The pessimist worries that the optimist is right.
Characters:
Dayereth, Eladrin Wandering Swordmage of Assault (level 15)
Masek, Longtooth Shifter Cleric of Berronar Truesilver (level 9)
Elithandre Rayne, Human Wizard (level 4)
Zuni Alta, Half-elf Swordmage-Warlock (level 3)
Jin, Changeling Bard of Cunning (level 2)
Nyx, Gnome Psion (level 2)
Quinn, Human Avenger (level 2)
Auken, Goliath Warden (level 1)