I declear Winter Envoy this year my luckiest summoning banner by far!
I just got the last unit I wanted and needed, Santa(!)Lissa
She's +ATK -RES
(31 RES is decent so -RES is acceptable in my eyes)
I calculated as well 'cuz why not (since it didn't take that long this time). Spent only 90 Orbs to get all four Winter Envoy units plus a pitty breaker Ninian.
This was very lucky indeed.
And I even have orbs left which I can save up for a future banner to come so this banner to pull on this year was amazing and a true christmas gift from FEH this year!