He spawns into the Tower Friday at 10am GMT (aka daily reset time) until Sunday 10am (reset time. His placement is random, he can be any of 6 places (that I have seen) These include: Near the speaker - by the railings or by the circular door Near crucible or vanguard vendors underground In the hangar - by the railings or in the underground bar. You will normally know where he is by the amount of guardians grouped together with the '...' symbol next to their names. Need Strange coins (up to 23 per item) and motes of light (up to 23 per item) to purchase things. Hope this helps.