You need to constantly get a 10+ win streak to get to eternal league in mythic league and very low loss chance. Also you need to be actuve and play for a bit. When I added mythics, my win chance increased enormously and I advanced really quickly to eternal league in a flash. It doesn’t matter what place you are in mythic league but as long as you reach the top 100, YOU WILL reach eternal leagie. Eternal league is pretty hard because you wil constantly face the meta which is camping rogues, blinkers, moving guidedshot ppls, tank builds and just any hard build. You need a real good build to reach eternal league. You need to be able to deal fast dmg, be faster, high win chance and stealth. Stealth is a staple most of the time to get to eternal league and to get higher too. If you have high dps, trickster can help alot too if thats possible in your builds. You basically need a proper build to reach eternal league with high win chance, high dps and less chance of losing. Fast fast dps is always crucial. Since my pvp build is aftermath proc build, it is fast, attacks with stealth if stealth proc activates and dps is fast. Its always fast fast dps that wins and most of the time, fast movement speed whether its by enigma, orb, shatter, charge, knights charge and more… Tankiness also helps a huge amount if your fast and deal fast dps. I only have 3k hp but i have high chance of survival because of sanctuary, legend trophy and decent stealth chance. I cant have stealth skill because then I can’t move and deal huge dmg as fast as I want to.
Aftermath is best with trickster for more dps but if you use different builds, you can have cooldown reduction builds or specialist affix if you can.
For high dps, you need to consider the element you use, the dot speed or dmg by element and dmg multiplyers as well as overall dps from weapon dmg and elemental dmg. If you choose the fire element which is a big staple in arena anyways, you need to make sure you can have high ED chance first from coat procs, nova, or Red ED and if wizard, you can use sorcery although that doesn’t do too much. Then you must have weapon dmg on both OH and MH as well as 5k Element dmg+ on every piece of equipment (optional:pet if you can). Afterwards, the good stuff can come from how fast you attack and to increase dmg for fire, inferno speeds up dps so it dmgs in less time. For more dmg on bleed, you could have bleed dmg epic affix or vampiric touch or both since bleed is from blistering which makes bleed do the %dmg fire does each second. Whats good about bleed is that it does the dmg that fire does and it lasts longer but still high dps. Then for more dps from weapons, offhand and element dmg, high crit chance to one shot alot of people at the beginning from 45% crit chance, 225% crit dmg cyan affix (optional: with sureshot) and if possible, add cyan deadly or mythstone deadly strike ( brutal mythic if possible). Red Ed can then easily double or triple elemental dps and if you plan to use red WD% it increases weapon dmg alot! Then afterwards, you can add more crit dmg, attack speed if you want, cooldown affixes, mana affixes ( energy is a good example), hp affixes if needed, spell procs if you want and many other really good stuff. It all counts on how fast you deal dps, your survivability and how fast you are.
Obviously you won’t be invincible and nobody can ever be 100% invincible but you will get into eternal league for sure. Mythic 3 and lower have meh builds and eternal league is where the competition really begins, eternally.