Dread banner/War banner

Thanks for the answers !
Actually, I did notice most of what you said in the meantime, but for some curious reason, nothing (at all) showed at first. I really don't know why, nor when did those visual effects finally started to show - maybe after casting it again several times or swapping the gem in and out, as I eventually did -, but everything seems fine now.

Cheers !
BenjaminK