Playing on the word "invincible", this domain gives a sense of security and strength.
The name "invincer" has eight characters and three syllables. Established brands using three syllable names include Mastercard, Toshiba and Adobe.
Invincer.com is a .com domain. Dot com domains are the most sought after domain extension in the world, famously used by websites like twitter.com. When most people think of a website, they think of a .com.