Giving double strike isn't in 's "pie" currently. Neither is giving defender outside of like Time Spiral with extra justifications. They would however be both in 's pie. In comparison to giving defender or double strike, giving last strike (which I assume to be the opposite of first strike) seems quite weak and like the "mode" that would be vastly underused.

Making creatures lose keywords I could kinda see maybe in I suppose. That ability however has serious memory issues - how are you going to keep track what exact keywords whichever creatures have lost throughout the game?

Putting -1/-1 counters on creatures is almost strictly a black ability outside of very specific circumstances and in green, the color along with blue known for its lack of removal, having that is extra egregious. Also, mixing both +1/+1 counters and -1/-1 counters is generally not recommend and hasn't been by WotC notable. It's pretty easy to get the two mixed and it's all around confusing to have both floating around. The ability should say "put" instead of "place" btw.

Balance-wise, repeatedly giving permanent defender to creatures as a plus loyalty ability means it acts as a sort of pseudo-removal soft-lock just on its own, which seems quite hard to deal with. I really wouldn't have that be the plus ability here. Given the balance and color pie considerations, I would maybe from the top-of-my-head give this a mana cost of - supposing the abilities were locked in stone. While the last ability would still be a stretch for as well, it wouldn't be as big of one as it would be in and could be maybe like an Elesh Norn, Grand Cenobite callback or something dunno.

IMO to keep the card in , it needs major rework.