I have and use Athena+8, Frida+19 and Lepus+19. They can all fire in 9 tiles because of talents and/or mana troop. The regular and elemental defense down stack, ensuring high chance of killing 2-3 enemy heroes when Lepus fires.
Richard is my first 5*. I loved the guy since he has helped me way back when I was a fledgling player in 2018. Unfortunately, he is still stuck at 3/70 since then, with the scopes going to Athena, Frida, Lepus, Ariel, Vela, Snow White and Miki. But I promise the dude he’ll get the scopes next when I get his costume since I have 17 in my inventory.
Thorne, I am also leveling him currently, but only to 3/70. I am not really much impressed of him. He may hit harder than Richard, but that is all. At least Richard is much sturdier and has attack debuff to the target and nearby. His costume may also be great.
Magni, I have 2 of him both at 3/70. I badly wanted him way back in 2018 since the classic snipers were a rave back then. But somehow, with the current ice legendaries out in the game, he is left not much wanted anymore. I have Fenrir at 3/70 and they may be a good 1-2 hit combo. His costume version may tell a different story.
Isarnia. One of the heroes I also was yearning in 2018. She has very high attack stat and her defense debuff is among the highest since she hits and affects all. Got her for the first time early this year from Hero Academy (I am still missing only Elena but the effing HA never gave me non-S1 hero even if it was churning nonstop since September 2020). I will be working on her to 3/70 after I get Thorne to that level too, currently at 3/67. May ascend Issy if I get her costume.
In sum, most of the S1 heroes are worth investing their color-specific ascension mats if you have their costume. But I do understand that getting one is just also threading to the needle or looking for a needle in a hay stack. Somewhat nearly impossible, especially for F2Ps. But at least it is not impossible.
Also, allocation of emblems may be a point of consideration. I have a few maxed legendaries unemblemed and they rarely see action in the game.