The "Who's Your Daddy" method

When you kick the ass of something strong, it has to serve you.

If you kill a worthy foe, you may again use your Pictish Design skill to try and capture the spirit and bind it to your flesh. The following artistic caveats apply:

1. Make it a design, not a picture.
2. Design must evoke an animal with the qualities you want.
3. Must be on the part of the body that you want to enhance.
4. Design must look good there.
5. Must also be BIG and impressive.

EXCEPT now instead of a single skill bonus, you have gained an entire Feature or Affinity, which gives a bonus to ALL relevant skills. How big a bonus depends on the spirit you capture, and on your artistry:

100 pt foe - Pictish Design roll:
Succeeed by 10 = +1 to relevant Affinity
Succeeed by 15 = +2 to relevant Affinity

200 pt foe - Pictish Design roll:
Succeeed by 5 = +1 to relevant Affinity
Succeeed by 10 = +2 to relevant Affinity
Succeeed by 15 = +3 to relevant Affinity

300 pt foe - Pictish Design roll:
Succeeed by 5 = +2 to relevant Affinity
Succeeed by 10 = +3 to relevant Affinity
Succeeed by 15 = +4 to relevant Affinity

Etc.

It's up to you whether to do this temporarily in woad, or permanently in tattoo, or to try both. If you mess up in woad the first time, you don't get to try capturing this spirit again.

Note:
This method will NOT work to gain a peace and love kind of ability, such as the Affinity of Beneficence (which gives bonuses when healing, ministering, or nurturing living things).

Revival time

When you bind a spirit this way, you also automatically avoid penalty on your Thrash- or Angst-o-meter from injury or illness that you are suffering AT THAT TIME. The intake of extra spirit revives you, though you still need healing. It does NOT offer you this kind of protection the next time you are injured (unless you are binding the spirit specifically to give you some kind of Affinity for Health).

Additional warnings
As well as the daily ritual that goes with the Lucky Socks tattoos, note that the animal spirit trapped in your flesh will cause and additional geas that restricts your behavior in some relevant and symbolic way, and the other players get to chip in their ideas.

Again, if you fail to pay it respect, the spirit is free to jack you over and then desert you. If you particularly anger it, it might just stick around and KEEP jacking you over. ;)