Urd limited banner
Dawn solo banner
Reroll for Urd.
Simple Rerolling (Don't start with limited units): Same process as always (Link to guide)
Advanced Rerolling (Start with at least 1 limited unit): Use the Advanced Rerolling guide (Link)
Trist from last week has proven to be disappointing. Top players, especially the ones who actually play RTA for fun, have been seen making her work, but that's in spite of her weaknesses. They have the gear, units, and skill to make her work, you might not.
2.5th anniversary is relatively soon so if you aren't literally dying to have Urd you should wait a little longer and get her from the limited combo banner.
Skip Dawn obviously.
Resupply this weekend.