Okay the more I am checking out the potential Mythical Relics I want to craft for my Blademaster the more I dont see those Relics being “Mythical”. They at best have a few extra stats in them. Are they supposed to be clear upgrades from lvl 35-ish to lvl60-70? They seem pathetic, namely Belgothian’s Carnage and Nemesis compared to Slaughter.
Could somebody explain to me why I get a tiny minor stats boost while losing other stuffs?
I really think Mythical Relics should receive a huge stat boost.
It is not the stats mainly that makes mythical relics better. It is its granted skills/bonus. For example, Nemesis relic has Summon Nemesis skill and that beast’s damage scales with player damage bonuses which is awesome. You should try those relics for yourself and then share your experience. Don’t trust the way they look on paper 
I think choosing relics require only how it will satisfy you.
If you’re happy with lv35 relics and keep mats. It’s always fine. When someone ready to maximize his char to the best and he thinks he may want mythical relics. That’s the time to find mats and make one for himself.
I still interesting in an lv35 relic like “Conflagration” those contain a beam skill and can combo in 3-beam skills with Albrecht’s Aether Ray and Tome of the Arcane Waste. (I saw awesome pics from someone comment those inspire me up)
Conclusion. I think Mythical relics provide better stats(maximize general needs) and more flexible in usage, some contained useful skills.
It is better in general usage, but may not be best for some kind of builds.
I can’t even begin to tell you how powerful Belgothian Carnage is. Just like the markovian Fortress set it reduces cooldown on your skills. The relic does 2 seconds reduced CD every 4.5 seconds. The difference is that you have this ability in a single item. You don’t need an entire set for it. It enables Shadow strike spamming, Pneumatic Burst spamming for more heal, Ring of steel spam, And other abilities from other classes. Like mirror of Errocets if Spellbreaker, you can have God mode on much more often with this relic.
I was skeptic like you at first. Just try it and you will see, you won’t go back from it.