I think I know what you mean. before this Asus I had a "point of view"
fx5200.
This card gave strange multi-coloured rectangles' and all kinds of
coloured "carpets" on hills in my Battlefied 1942 game.

This is exactly what I mean.

Question: Can this test or raised clock destroy my card or is it just
in indicator that I went to high??

The glitches just give you an indication of when you have passed a
particular point in temperature (and so you need to turn it down). Also,
as far as I know, overclocking any electical components so that they
heat up will shorten their life (but it will not kill them immediately).
You might knock about 5 years off the life of your card with a decent
overclock, but seeing as these things can last for 15 years or more and
given the pace of technology, it isn't that serious.

The next limit you will hit is the voltage limit - above a certain clock
speed, it will be unstable regardless of cooling because there isn't
enough voltage across the chips. Voltmods seem rather complex to me and
it may be cheaper to get a new card (the FX 5900 range is dropping in
price quite well - my FX 5900 XT is 4 times as fast as my old 5200, but
for only 2.5 times the price).