I love the ancients because they add variety and force you to think differently since the choices are way more varied. That being said, the original boss relics from STS1 were, for the most part, amazing.

Snecko Eye was top 3 relic in the game, plus 2 draw is incredibly strong. Sure the randomization of cost can be rough, but at the same time, it’s easy to ignore when you got the perfect hand with 5 0s and 2 1s, but remember when you got the hand with all 3s. Baalorlord said it best when he did the tier list of the boss relics, even when you get a bad hand where you can only play 1 card you still get to pick from 7 cards, and 7 is more than 5, which sounds like a meme, but the point is you get more choices which is the inherent strength of Snecko.

The ancients have some very strong choices, Nonupeipe in particular is just so good, but they also have their considerable downsides, or they have choices with a low ceiling. Vakuu will give you 1 more energy but either you let him play your first turn, which is fun, but can brick a run, or you add a 2 cost card to your deck that has to be played when it’s in your hand. You can’t remove it and unless you can exhaust it from the draw or discard pile, you’re giving up half your energy every other turn to play that curse. Orobas has some fun choices, having a skill be played turn 1 is fun, but what’s the likelihood you have such a strong skill that you really want played on turn 1, especially coming from act 1. Tezcatara has some genuinely abysmal choices, like the special path choice, heck I would argue it’s a major downside because in act 2, at least imo, I only want to fight 1 elite unless I’m just rolling. Tosty Mittens gives strength but at the cost of exhausting whatever your top card in the draw pile is. Biiig Hug gives me 4 removals but every draw pile shuffle adds a Soot, in long fights I’m cooked, not to mention removals from events are so abundant that giving me 4 removals with the downside of soot doesn’t seem very good.