Two Schools

Activated Teamwork Talent. Costs no action but always costs Strain; if its trigger comes up in the middle of combat, it also needs a Reaction Point.

Trigger: During a Skill Challenge, your bonded partner uses a skill different from one you have Ranks in, and you can describe how your different training offers a genuinely different angle on the same goal.

Tier 1 (Level 1): Spend 1 Strain to attempt a check with your own skill instead; a success counts toward the Skill Challenge's successes just like a normal attempt. If the Skill Challenge happens during combat, this also needs a Reaction Point.

Tier 2 (Level 5): As Tier 1, and you gain 1 level of Advantage on the check.

Tier 3 (Level 9): As Tier 2. You may also spend 1 more Strain to give your partner 1 level of Advantage on their own next attempt in the same Skill Challenge.

Tier 4 (Level 13): As Tier 3, but you may instead spend 2 more Strain to give your partner 2 levels of Advantage.

Tiers

Tier 1

Spend 1 Strain to attempt a check with your own skill instead; a success counts toward the Skill Challenge's successes just like a normal attempt. If the Skill Challenge happens during combat, this also needs a Reaction Point.

Tier 2

As Tier 1, and you gain 1 level of Advantage on the check.

Tier 3

As Tier 2. You may also spend 1 more Strain to give your partner 1 level of Advantage on their own next attempt in the same Skill Challenge.

Tier 4

As Tier 3, but you may instead spend 2 more Strain to give your partner 2 levels of Advantage.