I keep looking at the sight in front of me as the [Big Bang] happening. This is the least spell I have ever used in the Second Life. Not only because I need to chant in real life but also because it takes time to cast.
A Raid boss is hard and needs every second to ensure the entire party survives. Every raid boss dungeon has negative debuffs that need to be watched out like [Burn], [Poison], or [Freeze] to cleanse, and as the main cleaning player in the party, I need to watch out for them unless my party member will die from that negative effect.
Casting this thing will take my attention away from the battlefield and will not be good for my party members, especially when fighting the boss, who keeps casting negative effects as if it were candy.
I hate that kind of boss because the only way my mana gets to its lowest point is when fighting that kind of boss.