Right finally registered after lurking for way to long.
This type of event is sadly shit for f2p players. Coloseum was pretty great since you could get some reward every 30 minutes pretty much, so even if you could not get to top whatever because whales were burning puddings you still got a lot from it. Here you are pretty much screwed even if you managed to get some decent SED by semi no lifing in this game (currently 369k) it's still pretty much meaningless because you don't have any slayers. With current N slayer i have 443k SED and it is just pathetic compared to people with millions.
I have seriously no idea why they would make 2 elite guards event so close to each other, it can become disheartening to people that are not whales but do buy stuff from time to time. ESPECIALLY when you basically tell em "well thanks for money, your slayers are now worthless for 2nd part of event, buy more event gacha".