Invisible invader and unblockable WotG (glitches?)

2 different, yet weird situations happen to me minutes ago.

The first was an invisible invader. Ive seen friendly phantoms fighting invisible invaders (on 2 occasions) but for me this is the first time I couldnt see the enemy. I saw the "spirit invaded" message, one second later I'm backstabed and I die out of thin air. Name was someting like t343333333. I can only assume this is some kind of bug.

The second one was a guy that invaded and used WotG, and every single time, it went trough my Crest Shield. (!) He casted about 3/4 times and in all those occasions, despite me holding the Crest Shield up and he being directly in front of me, (no lag what so ever) the shield acted like it wasnt there! I dont know what the hell happened, its not broken or anything, my stamina was at 100%, I just took damage from all the castings he did, even when I backed up from him, he run to me used it again and BAM I took more damage and died. As this ever happened to someone?