Minecraft : Problem with 1.9 command blocks

Solution 1:

This wasn't a 1.9 change, but types have to be lowercase now: giant instead of Giant. A full list is here.

If you want to activate a line of command blocks conditionally, put a testing command (testfor, testforblock, testforblocks or anything else that can succeed or fail) into a repeating command block and place another repeating command block, this one conditional, so that its back faces the first command block (because that's how "conditional" works). A normal straight line of command blocks also works. Then you just continue normally with chain command blocks, they don't have to be conditional (but can be if you want to make them depend on the previous one).
How this works: The first repeating command block tests the condition in every tick, the second repeating command block checks for the success of the first one every tick, but only runs if the first one was successful and only then it also activates the chain command blocks in front of it.

For the future: Please only ask one question per question. I've answered both now because the first one is really trivial.