Basculegion Red Stripe > Use Agile Wave Crash 17 times
Basculegion Blue Stripe > Use Strong Wave Crash 3 times (Not 100% on this one, mine evolved quickly after using the regular one a bunch)
Wyrdeer > Use Agile Psyshield Bash 20 times
Overqwil > Use Strong Barb Barrage 20 times
ngl i'm quite a fan of this sort of evo methods.
It's something that can actually happen naturally or you can aim for.
The "happen naturally" is probably something that would work very well for kids too, I can picture a random 10 year old playing <insert pokemon game> and having his poke evolving right after the battle without having leveled up and they go like Pog
You're mostly right, but H-Decidueye has one niche over the other Grass/Fightings: Long Reach. Being able to throw off STAB Close Combats while not having to worry about Rocky Helmet, Iron Barbs, Static, Flame Body, Effect Spore, etc is a pretty neat trait for a mostly contact-based physical attacker. That being said, I don't see even this making H-Decidueye a more consistent pick than something like Breloom or Virizion.
That's also particularly notable when it comes to actual Smogon, where running stuff like Static or Flame Body on common walls like Zapdos or Moltres (and even Heatran! I'd never have expected that to see plau) specifically to punish the plethora of phisical pokemon and U-Turn spamming in higher tiers is normal.
I don't quite need to say how important it is to not get ruined by a burn on a phisical attacker (and paralysis isn't exactly welcome either).
Regular Decidueye was often going special, and one of his main stabs doesnt make contact anyway, so it rarely ever would make use of Long Reach (still does, a bit, if using U-turn and Leaf Blade or its priority moves)
Obviously we're still talking of a pokemon with stats that probably dont quite make the OU / VGC standards, but you never know, expecially if by any chance it makes it into the next limited pokedex format. Long Reach may be not as spectacular as Intimidate or Liquid Voice that the other gen 7 starters got, but it's still a decent ability for a phisical attacker.