What excactly do thesse prayers do?

Do they make it so it's favored in aperson with 95 prayer is it impossible to kill soemone iwht these levels!

with the new prayers? no. the deflect only have a 60% chance of doing anything, and if you're using full veracs then you can cut through it. for PvNPC, it will give you a huge advantage.
also, this thread should be in the runescape related questions forums.

they are decent for both pvp and pve however they are just improved versions of the regular prayers for the most part.
deflect = protect with a recoil chance
leech = normal boosts but also saps your opponents
wraith = retribution
turmoil = peity + a bit more boost dependent on what your fighting
berserker, the saps, and soul split are about the only truly new ideas

berserker merely makes it take a lil longer for stat pots to decrease at the cost of your prayer points.

soul split = 25% of what you hit goes to your hp (drained from other player's prayer if pvp) which is great for slayer as long as your not using it constantly it'll almost replace a healing familiar for most tasks.

and the saps merely lower whatever your fighting's stats based on what part of the combat triangle they are using.

while they dont make a person totally unbeatable tehy do give a bit of an edge over the regular prayers in pvp, but this is balanced out by a higher prayer drain rate as well as the high level requirement to use them.

http://www.runescape.com/kbase/guid/prayer_the_ancient_curses
^ all that you need to know.

Try google (http://www.google.com/) for obvious questions. Takes longer making a post than just google it.