I have Russell at 3-70 and 6 Rings (54 Hidden Blades).
But should I ascend him? Here are my current reds:
Elizabeth 85 +20
Azlar +20
Elena +19
Marjana +20
Boldtusk 75 +20
Yang Mai +6
Santa (maxed with Costume)
Natalya (maxed, no emblems)
Gormek +20
Boldtusk #2 +20
Carol +19
and 5 other maxed Red 4-stars
Only other current options for Red are Natalya #2 (mid 3rd-tier) and the following unleveled heroes: 2 more Yang Mais, another Santa, and Khagan (no costume)
He is not bad. You could ascend him, but you could also wait to get more rings and maybe you get someone better till then. If you have costume Kelile, he has great synergy with her. I would not max a second Yang or Santa. And since you already have two other slow S1 heroes, I would not max Khagan either.
So for me option 1 is to wait, option 2 is to max Russel.
Russel is the best choice out of the given options. His damage while a sniper quality is still decent due to his attack stat and the burn damage makes up for it.
You never know what you might pull in the next month with the S4 finale and S5. There are some decent events on the way as well (with the possibility of Black Knight Costume).
But it’s up to you, if you feel he will do a difference in your playstyle then by all means do it.
I like Russell with a very fast hero like costume grave maker or emilio… with normal grave maker… he’s still good… but I think 1 turn slower on his level… I leveled my russell… I like the guy… I like that dodge doesn’t affect him… when I take other heroes and dodge is activated… I wish I had him… but… based on azlar… I would say wait… maybe if you had 12 rings… sure… but at 6… it is a long weight if you pull a miracle hero next week.