With Ashaya, Soul of the Wild, this lets you put a +1/+1 counter on a creature whenever a nontoken creature enters the battlefield
Against any agro deck he is a poor tempo play, even when you get to shoot them for three or four you will still generally lose tempo over a deck making plays that impact more on the board with their three mana
Combat is a core mechanic of the game
The Full Art version does look impressive in its own right, but it lacks the sheer ferocity that this card emanates and has defined Red Gyarados ever since its unforgettable introduction
Other prominent mechanics that incorporate (or freely enable) sacrifice include: Food, Clues, Treasures, Sagas, Unearth, Encore, Evoke, any other temporary tokens such as Faerie Artisans or Hostility, cards with Upkeep, Quests, Exploit, Casualty and now Bargain
First and foremost I'd have to go with token all star Anointed ProcessionAnointed Procession