Some suggestions, not necessarily in this order.

1. Sign of Recognition - lets you see who else is in CoL. Can be used to mimic and respond to symbol of recognition
2. Sign of Communication - lets you access ESP, also lets you sign messages to other COL members in the room
3. Sign of Staunching - prevents blood loss
4. Sign of Warding - increases DS, TD
5. Sign of Defending - increases EBP, SMR and CMAN defense
6. Sign of Attacking - increases AS, CS
7. Sign of Aiming - increases chance of hitting specific body part with ambush or aim, and raises chance of hitting a better body part using bolt spells
8. Sign of Shadows - automatically hides you and increases chances of hiding/remaining hidden for duration; slightly increases ambush/waylay bonus; can be set to auto-activate to prevent spirit loss being visible if it is off cooldown
9. Sign of Fear - intimidates all critters in the room, and depending on how badly they fail their roll, make them suffer loss to stats, roundtime, or stun
10. Sign of Life Drain - instantly heals your health up to max; if there are critters in the room, drain blood from them to reduce all wounds by one rank
11. Sign of Mana Drain - drains mana from critters in the room to replenish your own, first drains buffs on critters and then their mana
12. Sign of Spirit Drain - drains 1 spirit point from a corpse in the room, destroying the corpse in the process
13. Sign of Sacrifice - instantly and brutally kills an incapacitated critter that is under 50% health, gaining a temporary buff to AS and CS. the body of the target explodes, dealing damage to all other critters in the room
14. Sign of Shrouding - shadows surround you, chance to negate any attack against you
15. Sign of Domination - takes control over a single critter, making it fight for you for one minute
16. Sign of Raise Dead - reanimates a single critter back into an undead version of itself, which you can kill again (like the EG necro rings)
17. Sign of Wracking - drains 4 spirit to replenish 200 mana
18. Sign of Possession - allows a higher power to possess your body temporarily (hopefully), massively increasing your stats, resistances, letting you cast through injuries, but you no longer have control of the character for the duration. During possession, you will attack nonstop, starting with critters, and if none are around, possibly other players. Very small chance that the entity does not give your body back at the end, in which case you die.
19. Sign of Darkness - teleports back to safe spot in town; can be used while incapacitated but has chance to lash out and injure you
20. Sign of Hopelessness - sacrifice your life and soul to create a giant mana explosion, dealing massive damage to everyone in the room (likely killing them), and temporary making room unsanctable. Instant decay. Possibly other RP penalties due to temporary loss of soul.