If you can't remain in your arena position because someone ELSE powers up the same characters you have access to.. well...
This is akin to stating "I didn't get The Beast during the event, so everyone should have The Beast taken away. He's too powerful." I'm amazed that people don't see it this way. Again, it's not like an exclusive character, talisman, or item proliferated. It merely fast forwarded some players, that's all. Shortened 6 months of collecting and building down to 2 months (because that gold will go quick and they still need evo runes/shards to power talismans). No one got anything "special" here. They merely got resources which will evaporate quickly.