A custom spirit; follows rules of a Companion Spirit from DMG 2. Be warned, it is a little bit overpowered, but it's meant to be as a story point. It is a combination of healing and communication spirits.
Your companion spirit allows communication through the magical conduits that bind members of your team, as well as providing a means of sharing magical effects and resisting the effects of poison and disease.
1st-Tier Benefit: Team members can talk to each other as though connected by a message spell for 1 round per day per each person on the team, split up as each team member likes. For example, if there are eight people on your team, you can use the message benefit for 3 rounds before an encounter, then 4 rounds later in the day, and you’d still have 1 round of communication left.
Also; Your companion spirit can hold a 1st-level spell, which each team member can release. Once per day, a spellcaster on the team casts the spell into the companion spirit (ignoring usual targeting requirements). At any point during the following 24 hours, each team member can release the spell as if it were a spell trigger item with a caster level of 1st, but the team member need not have spellcasting ability. The spellcaster makes all choices the spell requires (other than targeting) when originally casting the spell. Each team member can use the stored spell only once, and must abide by targeting restrictions and line of effect when casting the spell. You can’t use the companion spirit to store spells with a target entry of personal, and it won’t store 0-level spells.
2nd-Tier Benefit: The team shares a permanent status effect, as described on page 284 of the Player’s Handbook.
Each day the companion spirit gets a pool equal to twice the amount of team members in the party that any one member can use to add to his fortitude save to overcome poison or disease. For example; with 5 team members, a member who was just poisoned by a snake can use up to 10 points from the pool to add to his fortitude save to avoid initial damage, or can split it between both initial and secondary.
3rd-Tier Benefit: The team can send messages great distances through the air, as the whispering wind spell, though the destination of each message is limited to the locations of other team members. The team can send one such message each day for each team member.
Also; the spirit can now hold spells up to 2nd level and caster level can be up to 3rd level.
4th-Tier Benefit: Team members can telepathically communicate through a Rary’s telepathic bond for 1 minute per day per team member.
Also; the secondary 2nd tier benefit increases in power so that the pool is now 3 points in the pool for every team member. As well, the bonus may be applied to fortitude saves to overcome poison, disease, paralysis and sleep.
5th-Tier Benefit: Each team member can use scrying (as the spell) on another team member for 1 round per day per creature on the team. For example, with six people on your team, you could scry on one of them for 2 rounds and another for 4 rounds. You instinctively sense when a team member is scrying you, so you know it’s safe to intentionally fail the Will save the spell requires.
Also; the spirit can now hold spells up to 3rd level and caster level can be up to 5th level.